[jack]

I'm using Sonar 4 (by Cakewalk) for recording audio. Does anyone have recommendations for soundcards that work especially well with this? I would like to be able to record multiple sources at once with as little latency as possible and with at least pretty darn good fidelity. The card should also have MIDI capabilities. And (I imagine that this will require an additional card) I'd like to have surround monitoring as well.

 

[Mr.Radar]

What about the EMU 1820m or RME HSDP 9632? Both of those are pretty expensive cards but (I think) they fill all your needs. You sound like you're doing some pretty professional level work, so you might also want to ask at some pro audio forums (sorry, I don't know any).

 

[Budley007]

Most of your better cards handle I/O through a breakout box. This tends to be the industry method for shielding most of the electronics outside the computer case. Unfortunately, the caveat to this is that you're going to pay alot more than you would for a traditional soundcard.

I've got an Aardvark Direct Pro 24/96 that works well on a dedicated system. (drivers are a little flacky for a general purpose home computer)
It integrates flawlessly with Sonar 3, so I think Sonar 4 would be inclusive. Latency is extremely low with ASIO 2 drivers. Monitoring is zero-latency as well.

The only requirement you mentioned that it does not provide is surround monitoring. Some of the newer products you research may have this, but I doubt many of the older "tried and true" card/interfaces will offer this.

Goodluck with your purchase.