Well, I'd go with something a little more on the unusual side.
It's a very special birthday after all.
Go look for a HKP7. It's on the upper side of you're price limit, but damn, if it ain't nifty.
As for 1911's, on this I'd skip the RIA. Look for something a little nicer. I'd also skip on the Kimber. I havn't heard such nice things about the company. Check out Springfeild Armory.