i weigh in with a vote for the CADs if you need them nowish. they are pretty common.
CADs have a fun larger than life feel to them, although often i think they sound like shit on vocals for some people. personally, i dont dig the SD condenser OH sound, so i am biased.
however, for $500 if you wait around a bit you can get more creative.
first of all, you might want to rethink the need for a stereo image on the OHs. if you do that, and are willling to drop $500 on a single mic, you are gonna step up a class.
hate to give away a good deal i am looking at, but atlas has an MBHO 603 with a SD cardiod head on it for $450. now that is a classy mic. one for the ages.
as far as stereo pairs, if you look around you can get a stereo pair of lower end earthworks for about $500. i got
my sr69 for $250, two of those would kick ass. also you can get a pair of SROs for less than $500. those are really great mics. of course you have to be ready for OMNI mics if you get them.
jeez, you could also get a pair of beyer m260s for $500. will give you a TOTALLY different sound from any of those mentioned. they are my favorite OH mic, but you have to get ready for a different experience. they have totally smooth nice mids, rolled off top, little thick in the low mids, then they slope out of the way for the sub frequencies (dont get in the way of a kick mic, nice!)
really there are some big early decisions you need to make about the sort of sound you want.