I was thinking of going with Goodman as it appears that they have the best parts warranty.
Goodman has the best "standard" wrty (10 years parts/10 years compressor), however, not the best in the business (one brand I can think of has a standard 12 year parts, 12 year compressor and 12 year labor warranty).
As CB mentioned, labor is far more expensive than parts.
Example, a reversing valve may be 1/5 the cost of a compressor, but labor wise, with some guys, will cost you about as much (or at least half) to replace, labor dollars wise .
A little sidenote about Goodman and their warranty. Average time the homeowner will live in their current house is 7 years. Goodman's warranty is non transferable, meaning the warranty is only good for the original homeowner.
I know one guy who just dropped Amana (two weeks ago). Too many recent TXV issues. This isn't Amana's fault (another company makes the TXV's), however the guy didn't get anything for his troubles. That said, almost everyone has issues with TXV's sometime.
As CB said, get mulitple quotes, and go with the contractor you feel most comfortable with. That said, the contractor should at least do a load calculation on your house to verify the propper size of equipment, and the more information he gives you, usually the better. Also make sure your comparing "apples to apples" on competing quotes. One guy may only be replacing the equipment (and different features of the equipment may raise the cost as well), whereas another contractor is replacing duct work or adding a return (which usually costs more).
I'd seriously look at a R-410A unit (don't mention it, see if the contractor offers it). R-22 is at about the same price as R-410A now, and I remember when R-410A was 12 times the cost of R-22. R-22 equipment will cease in production in a couple years as well (and next year, I assure you, R-22 will cost more than R-410A, and that difference will only get greater as time goes on). It's a very good idea that if you replace a R22 unit with a R-410A unit, you should change out the lineset. R-410A and R-22 have different oils, which are not compatible with each other. You can run the lineset outside of the house, I'd suggest a cover for it though (most guys will just use gutter pipe, however, there is a "cover" system for the lineset that is made just for that purpose, looks really nice, but of course more money, but it may keep the wife happier).
Remember this, if you go with a R-22 system now, 10 years down the road if you have a problem with your outdoor unit and it needs to be replaced (for whatever reason) it will be a very interesting scenerio if the compressor isn't available (and that has happened in the past). You run the small risk of having to replace the entire system. Not a scare tactic, just a possibility. Personally, I see too many guys in the HVAC field thinking that there is some other "magic" bullet that will replace R-22 because they refuse to install a R-410A system because they are afraid of it (higher pressures and very sensitive to moisture). Fact is, if your contractor is installing a R-22 equipment properly, he knows he won't have a problem with R-410A. Carrier has had the "Puron" (AKA R-410A) out for some time now (close to 12 years now?). Most of the Carrier guys I know sell NOTHING but R-410A.