Yes, you will get a gold star, but be forewarned it will just stand as proof that you can do practically anything.
We're getting ready to change the heater/AC and my wife is looking at me.... She may as well, however, since I'm sure as hell not paying some contractor 20k to do it.
HVAC stuff is one of those things... my brother does it for a living. When he worked as part of a bigger organization, he got huge discounts on the units. At a smaller organization they get much lower discounts, and individuals can't even buy. Those AC units that people get charge $5k installed, one company he worked for was buying them for like $500-750.