Are the AT's you have in mind fixed or modular AJ?
In the OP's price range I think you'd be looking at fixed, like these:
http://www.sweetwater.com/store/detail/AT4041SP/or these, for $50 less than the AKGs.
http://www.sweetwater.com/store/detail/AT4021/The 4021s are, IIRC, the same thing basically as 3031s, which IMHO sound better than those AKGs. But it's a difference of flavor; the AT's are a bit cleaner sounding but don't have the fat, round bass response the AKGs have.
I think to get switchable cap AT's, you'd have to go to the 4050 series, which is substantially more (but are great mics).
http://www.sweetwater.com/store/detail/AT4051I've run the AKG 91s and AT 3031s and you can't go wrong with either, but they are different creatures. If it's important to have actives and switchable caps the AKGs are the way to go. If I just wanted a really nice card at a decent price, I'd listen to LMA samples and decide which I liked better, but I'd give the two AT models a hard look.