We actually are sort of trying to get rid of a "classic" swing keel Mac 26 in New Mexico... getting around to fixing a few things at some point.
But, having said that, I think you'd be happier with a smaller boat to start with.
If you really need a cabin, Arizona has an active fleet of Catalina 22's that you could sail with and get lots of help from the group. And, although there are not as many in Arizona, the Santana 20 is lots of fun, zippy, and has a mini-cabin; tons of them are available nearby in California.
And if you don't need a cabin, elsewhere, I mentioned the 18' Buccaneer dinghies
, which have the advantage of a huge local fleet and lots of fun. A Bucc would be a great boat to learn on.
I'll have to warn you about the Arizona Viper fleet. These 21 ft. sportboats are incredibly seductive. They are very fast and powerful and will hold their own racing against bigger boats. They are all in good shape, since the whole class is fairly new. However, they are not for the faint of heart and they are not cheap.
Then there are the usual suspects .. Flying Scots are popular in the midwest, O Day Day sailers (16'), etc.
You've been warned about the attitude of some folks toward the MacGregors; there is also a similar set of attitudes directed at West Wight Potters, although the WWP's do look much cuter.