No lower than XR series HP condenser paired with Tam7 var speed air handler.

What size is each zone?

Total 10 tons of cooling?...

IMO

In a residence; 5-Ton systems seldom deliver anywhere near their Rated Performance, due to lack of enough airflow & other design engineering shortfalls.

The important factors toward generating utility savings is to Improve the Energy Efficiency of Your Home so you can reduce the size of the equipment.

Then you optimize the duct system sizing plus return air filter area sizing; seal the duct system with mastic & highly insulate it if not in the conditioned area. This is where a software Load-Calc along with Proper SIZING is a Necessity.

Use a programmable temp-swing adjustable thermostat to increase the run-time & off-times. These are the factors, among some others, that will improve the chances that the new system will deliver a decent EER & SEER performance.

The only thing that counts in air conditioning & heating is "Delivered Performance to the homes' conditioned areas"

Another real PRO states that in some situations the use of a 1" deep pleaded filter can drop a 14-SEER to an 8-SEER. How many buy & use those high pressure-drop filters?

The only thing that should qualify for a REBATE by power companies & others is the "Tested Btu/hr EER Delivered Performance."

Here is a link that might be useful: Why HVAC Systems are Less Efficient than U Think

Thanks for the replies. Tigerdunes- we've bumped up but only to xb14 with tam7 to get the variable speed. Upcharge from xb13, this is costing $2100 for the two units. I will explore xr pricing as you suggest.
Our sqft breakdown for the zones:
1207sq upstairs x3 bedrooms/ baths (three kids) thermostat and return in one bedroom
1528sq ft upstairs remainder thermostat and one return in hall
1216sq ft downstairs master, m bath, closets, study thermostat and 8" return in master
2571sq ft downstairs remainder thermostat in hall two other return is two different hallways
4 pro 9000 thermostats. Honeywell
Install HV modifier
Yes, ten tons total. I was told we are a bit over in tonnage for upstairs but trane doesn't do half tons? Any further suggestions?

Udarrell- thank you for responding. Your response was like a foreign language for me! :-) I read it twice and asked the HVAC guys some questions. Some info- train tam7 injection insulated plastic cabinet, variable speed motor, one in the crawl, one in the attic.
Mastic is code for us. These guys use really big zip ties, pandit straps, duct tape, and mastic. Duct will have r8 insulation. The flexible lines are preinsulated, metal boxes and manifold will have r8 they put on. What do you suggest we use for a filter? By filter do you mean the things I change monthly that are inside the house or something more permanent in the units themselves.
Thanks again.

This post was edited by BINK5 on Fri, Apr 4, 14 at 21:06

"What do you suggest we use for a filter?
By filter do you mean the things I change monthly that are inside the house or something more permanent in the units themselves."

The filters you change monthly
. A huge factor is the amount of area for the filters; you'll need at least two filter areas for each A/C system.

Tell us the sizes of the filters & the cooling tonnage/CFM airflow they have to handle.

If you use pleated filters you'll need to use the deep ones; tell us what type filters you're using & their depth in inches.