The Presonus stuff is an improvement soundwise over the M Audio. We have two M Audio FW 410's in our uber-portable gear at the university and they sound ok when recording, but we dont typically use them for that. Mainly they are used for feeding sound into a program, then garbling it up or using it for other purposes rather than just recording. Mainly our interfaces are just 8 + channel playback devices for live audio, but we run the hell out of them. That said one of the two FW 410's does not work on my professors PB, our PM G5 and sporadically works on my PB. We still are not sure why, so it is just collecting dust at the moment.
Our recording services dept recently bought the Firepod to record our large ensembles when they are not performing in our performance hall. Our first test of this was the jazz band performance, and it turned out quite well just using the built in mic pre amps, though next time we will probably use one of the other mic pres that we have just to have a comparison.
As far as the Lexicon i have not used any of their interfaces, but it could be a diamond in the rough.
Another sound card came to mind, the
Focusrite Saffire. It is at the top of your price range ($399), but it allows for some on-board DSP to ease CPU load. For instance, if you want to record with some reverb, the Saffire will handle the reverb without placing extra burden on the CPU. I just thought since you mentioned that you have an iBook that this might be an advantage. I know that Wintermute was pretty much giddy about the Saffire when it came out. I played around with one when i was in Indiana about a month ago for a concert series. It sounded quite nice, but this is from more of a cursory use. I just wanted to throw the Saffire out as another possibility, though i still have my vote for the Firebox.
The main thing is dont get overwhelmed with the choices. Keep it to two or three and weigh price vs. performance. For instance i really want the RME Fireface, but at $1499 it is not worth the price for my needs. As for a good vocal mic, i have no clue. I use a old, old SM 58 for all of my vocal stuff but i dont deal with vocals much. I have heard some good things about Oktava mics, but i hear the quality is hit or miss on them. Some US retailers test all of their Oktava's before selling them to weed out the bad ones, but i cant remember the name of the company that does that right now....Others are more qualified to advise in the area of mics and
Mic Preamps.
Oh, just noticed on Sweetwater that they have a
Firebox B-stock (refurbished) for $259.