Considering what you have now, for $2k I'd get something like:
$200-$500 - Interface - firepod / motu, whatever 8 channel interface. If you're absolutely 100% positive you'll only ever need 2 channels, you can save a lot here and get a USB mixer or whatever 2 channel interface. Something as cheap as
a Yamaha mw10 is a great deal for $150 or so. But like gcapel said, you'll be screwed if you EVER need 3+ mics at a time (drums). IF you decide to save a few hundred here, I might spend it on another condensor in the $300 ballpark like AT4040, SM81, SP C1, etc..
$200-$300 Room treatment, 8-12 diy 4'x2' 703 panels. If you have nothing, a little goes a long way here.
Some dynamic mics:
$200 - A couple 57's or audix i5's, etc for drums / guitar amps, general use
$200 - A d112 or audix d6, etc for bass / kick drum
$200 - A few cheap headphones for tracking, + headphone amp. Even some AKG K55's and a behry amp, you could probably pull off for $150. SQ isn't important here.
If you don't have the cabling to connect it all, add a couple hundred bux..
The rest on the best monitors you can get, I can't tell you what's good in the $800-ish price range, but I'm sure someone can. Even if you spend $500 on the interface, you still have a good chunk of $ here.