It sounds like a person could block inbetween the joists to change the direction the decking would run,or header off install new beams and run the joists inbetween them,or take all the joists out and reframe. Joists hangers installed no matter how it was done.

First up is a real good inspection of the frame and foundation including the conection to the house/flashing.

It would be better for You to rent a fork lift or whatever rig it would take to get your material from the truck to the site. J.

If you change the joists so they're parallel to the house, they'll be long and would need to have added support from a beam installed underneath, perpendicular to the house. Either that or just add blocking, like John said.

I absolutely second what he said about checking the framing as well. I've seen a few decks in the past year that scared me: one ledger board attached to the brick facade with a single tapcon screw, one just nailed, several without any joist hangers. Codes have changed a lot in the past 20 years, and many old decks are could use some shoring up to be safe. Post a few photos of the undersides of your decks and we'll be happy to give you free advice on what, if anything, to correct.

We bought our decking from ABS Wood, and they shipped via Hot Shots. They drove their truck around back (we have a big lot) and we offloaded with Mr. Weedy's tractor.

Current joists are parallel to house. Would be changing to short joists if I change them. Only outer frame would need to be strong to support the new joists.

Main deck (roughly square 22'x30' on steep hillside)
Construction was definitely substandard. A portion about 1 ft off the ground collapsed. It had been attached to the side of the garage with regular nails. Redid frame as a free standing deck with its own footings and posts(notched top of posts and carriage bolts/lag screws used.) Based on a 2x8 frame with 2x10s on taller part. Had thought of replacing diagonal boards on main deck with boards perpendicular to rafters, but on further research, deck lacks any bracing against twisting. Posts are simple vertical posts with no triangular braces and no diagonal cross pieces. My understanding is that this is Ok only if flooring is diagonal since flooring provides the cross bracing. So easiest to keep main deck diagonal.

Two narrower decks-12 feet high)
Much more sturdy. Tied into house with bolts and based on 2x10 frame and rafters. Uses 2 2x10s surrounding 6x6 posts, notched tops about 12 feet high at outer edge. House walls jut out between them providing side support(the larger supported on two sides, the smallest on 3 sides)
Looking at it more closely, if I proceed with changing direction, I am leaning toward blocking only. Too much work redoing larger beams. Have a lot of leftover short pieces of 2x8s from fixing lower deck-so if cut to length, could use here-just need to buy hangers and nails.

Original deck boards were cedar, painted with regular paint (which peeled badly) to try and cover extensive rot. Replacing this extensive rot is what is making me redo the deck.

Another issue is a long staircase. Currently not to code for a variety of reasons. Uses 3 16 foot 2x12 stringers supported at both ends only(against deck and ground). Steps 9" deep. Needs to drop 12'8" on a horizontal run of 12'. Open steps with over 4" gap between steps. Rotting, not to code stair rail. Give the size, this will be a challenge to put up, particularly if use a heavy wood like IPE for the stringers(also expensive). Would be nice to have longer run, but run extends to end of concrete area in lower level. Would also be nice to have rail slightly further than bottom step, but size of space makes things difficult.

Changing board orientation would allow using short(cheaper boards). Going diagonal will require using 10' boards for same segment. Can cut waste some by using 40 degree angle as opposed to 45 degree(stronger than 45 degree since less effective span).

Biggest problem is still delivery logistics. I can not unload the amount of wood needed myself. I have someone who will come in and help with install, but can not be available for a delivery without a bulletproof delivery date right at the start of install(flying over to visit). Driveway will not support a tractor trailer turning around. Do not have any equipment heavier than a lawn tractor and flat pull cart so can not move bundles around. Will need to break bundles to move boards. Have never used fork lift and even if I rented one, would need to be sure delivery is on date I rented it. (would need to be delivered--I do not have a trailer or even hitch to pick up with). Either I have to order boards in smaller quantities or order from a supplier that brings along a miniforklift on the truck to move bundles to end of driveway.

If your geting the ipe from an out of state supplier its possible for a lot of money they would search around and handle the whole deliver for you.
The Supplier sells lumber for the most part then contracts a Fright Co to haul it to a local dock. Its in the contract the Fright Co agrees to to deliver your load to your house not unload it. This is true with a local supplier as well.

In other words if you want to pay a Supplier some major change to baby sit your delivery I am sure some of them will do it However you would be money ahead by far doing a little phone work yourself. A couple of things come to me... get your friends to help you unload the truck, Call a temp labor outfit, I use Tradesmen , to send you a couple of workers to unload the truck, Call a local lumber yard and hire a couple of workers to help you unload the truck. There is no bullet proof delivery thing down to the min with a Fright Co you get it when you get it like calling for Cable repair. There is however a bullet proof time when the material is in the hands of the Fright Co and its in the Contract they will load it on whatever you bring to the Dock soooooooo the best sure thing is to rent a truck and a trailer, get a couple of big ol boys to unload at your house.

With all the money your going to spend on this project geting the material to the job site is the least of your problems so buy the lengths you want. J.