qooldude,
You might look at the variable speed pumps. They are more expensive, but you can eliminate the jet pump to offset the cost.
One heater for a pool/spa combo is good. The heater use for pool/spa combos is generally geared toward heating the spa and the pool is secondary. Use a 400,000btu for the shortest heating time(about 20 mins depending on outside air temps.) Not much cost difference using the larger heater.
If you use a cartridge fiter, use as large a filter as possible(300 sq. feet or more). This will give you longer cycles between cleanings. They are kind of a pain to take apart and clean. My experience with Sta-rite 450 sq. foot filters is cleaning cycles of up to one year intervals or more. It's practical to clean once or twice a year.
Install an automatic water fill if it's not on your list.
Good luck with your project.

Two pump systems are nice because you can bypass the pad equipment for the spa jets and get the most of the jet pump. Also, you can run the spa jets separate from filtering the pool water.

If you decide to go with a single pump, make sure you have a bypass built into the equipment pad so you aren't forcing high velocity water through the filter and heater which would make the jets feel weaker.

But if you go with two pumps, the main circulation pump doesn't really need to be that big unless you are running other water features. A 3/4 HP two speed would be plenty big for just circulation.

If you have high electrical rates, a VS may be more economical but you can get most of the savings from just a two speed.

First and foremost you should look into variable speed pumps in place of the Trisar. In Canada they have actually stopped the tristar pump series completely in favor of the new generation variable speed models. They really are worth the money.

If you decide to zone in a 3 zone bypass on your heater as suggested above to limit the water running through the heater, be sure to look into the requirement for a pressure release valve to be installed. In my area no bypass = no PRV however as soon as you add a bypass valve then a PRV becomes required by code.

A 400,000 btu heater is more than enough for your pool and hot tub requirements. Maybe even a little less however with this style of installation the tub stays at pool temps until you call for heat at which time you are looking at about 20-30 minutes to get the spa up to 104.

I did not see any valve actuators on your list - they might be included with your goldline panel but be sure as you will need them.

Seriously though think about the variable speed pumps. Both Hayward and Pentair offer one now but order early. Last year the Eco-star model was on backorder for almost the entire summer. They are also the quietest pool pumps that I have ever heard. You can read a little more about these variable speed pump options if you are interested at the link below.

Here is a link that might be useful: Variable Speed Pool Pumps