I have a 30 year old colonial (about 2500 sq ft)in NJ with forced air heating and cooling. I want to accomplish 3 things by upgrading the system.
1) zone the house
2) cool a family room extension (facing south and has many windows).
3) lower costs

I have 2 quotes ...

How to zone the house into at least 3 zones basement, main floor, and upstairs is conflicting in the quotes ...
One says use arzel (quieter, non mechanical won't break etc...) easier to work with existing ductwork ... the other says Zone a Trol and replace some duct work ... which he says is too big for the furnace anyhow. I have read elsewhere that zone a trol (an older technology) is mechanical and therefore can be nosier and dampers break.
What do you suggest in terms of zoning technology and why.

Both quotes suggest a ductless AC for the extension .. OK that's consistent ... they said it would not make sense to just make that room a zone ... it's about 16 x 12 ... and furthermore it does not have ductwork and would be costly. what do you think of ductless AC?

Both quoted a furnace replacement ... one a trane variable speed xv90 100k btu and other other a trane tud140c960 140k btu. One says the variable will save $ and make the overall temp in the house more consistent. the other says you don't need it? What do you think of the variable speed furnance.

Both also suggest Trane AC unit one a 5 ton 13 seer and the other a trane 4 ton 13 seer.

I really want to move forward but find it difficult to figure what is the best solution. This is a costly investment and we want to make the right choice. thanks