Re: Suggestions Please
For USB, I'd probably go with a Lexicon product. My friend uses an Omega and has gotten excellent results. On the firewire side of things, I'm partial to Presonus stuff since I've had good results with their Firestudio. In your price range, I'd look at the Firebox. My system is a PC so I never really considered at Apogee, but they also make great stuff and are highly thought of.
That being said, I'll defer to people who actually own these or similar for better recommendations. I use the Firestudio with the faderport, which I got used off of Craigslist for $425. If you're not averse to something used, I'm sure a little research/patient searching could produce a similarly good deal.