24's = looks
22's = looks/performance
20's - = performance
unless you buy cheap wheels that are heavy....
if you go for 24's you'll lose a considerable amount of performance comfort (handling and loss of speed, unl;ess you get expensive lightweight multi-peice forged), you can't make the fx lower unless you do other custom work to make it work properly, plus you can damage the wheels more easily.....
(plus since you're paying don;t listen to the WIFE, do what you want to ...22's)
if you go 22's, there will be barely any loss in comfort or performance compared to the 24's, you'll still be able to lower the FX without any other modifications (depending on how wide the tires are), and you will have a bit more tire than the 24's so less likely to get as damaged from road conditions.....
in my opinion, I would use the money from getting 24's and get some lightweight 22's, and lower the FX....you will not lose the performance, youll be able to lower it so it's not as high as a tahoe, and there will be a significantly less amount of gap between the fender and the tire..... I have 20's and there's only about 3-4 fingers' worth of space between the tire and the wheel well.... so think about how much you want to spend first, then go from there.
on the other hand, if you don't care about performance or handling (why get an fx then?) or lowering the FX at all, and you just want some Ballin' wheels, go get some 24's...
my opinion...go for the 22's