I use the Sound Devices USB Pre in my studio & on the road.
the biggest plus is it has an awesome mic pre-amp…really high quality. It will also take ¼” inputs, digital inputs, etc. It’s very well built, and it costs $550 or so. I just bought one on ebay for $350 so I can keep it in my road bag, so you can sometimes find them used, but not often. I’ve been looking for six months.
Another one that might make sense would be this one:
$225 or so. One benefit would be the ‘insert channel’ so you could run a tiny compressor or something similar to make sure the sound was already compressed a little on the way in to the computer. If you want a really good compressor that is tiny and cheap, this one is the best there is for under $500:
looks like junk, sounds really good. It’s $199.
If you wanted to go as cheap as possible on the sound card, the one that would still sound 90% as good would be this one (it doesn’t have the insert patch for an outboard compressor):
it’s about $150.
If you want to get a great mic that is good at rejecting side noise and stuff, one mic I use often is the Sennheiser MKH-416 shotgun. You can sometimes find them on ebay for $750 used, they’re $1000 new. Just make sure you get the P48 version (phantom power). It should be black, not the silver one.
I usually get the best prices and cheap shipping from a guy at Full Compass. Call Martin Vire at 800-356-5844 x1179. He’s also really good with advice and is usually dead on with his suggestions. Feel free to drop my name to him.