re: Interface with Midi and 2-4 inputs
? do You mean 2-4 Pre-amps? and also do You need High-Z (Guitar-Bass)
I bought a new Imac and my USB 1.1 Tascam US-122 has no Snow Leopard Drivers (see the 4+ page thread on that unit)
I decided againt using-trying a Powered USB hub as its USB 1.1 anyway
I decided to go Firewire though USB 2.0 is o.k as well
Do plenty pf research and make a list of what You need to plug in, etc
I looked a Focustrite Saffire (both USB and FW) Lexicon US42S USB 2.0)
T.C.Electronic Impact Twin, Mackie (FW and USB) and also Presonus FW
I ordered a T.C.Electronic Impact Twin and its due to arrive 12-28-10
I took my time , it has two combo XLR-1/4 ins (both high Z) Spdif/midi in-out
1/4 ins and outs and also ADAT in-out (which allows future tinking to add on 8 preamps (if needed) I looked at Mixers with FW and USB in but most lacked MIDI, I read the forums on each web site and not company website
and the drivers for T.C Electronic are strong and historically they are proactive with updates (with Mac's and OSX 10.6.5 now (I am running 10.6.4)
can be a pain for develpers as Windows does not change as frequently,
I ruled out companies step by step due to various issues though I think they all were overall very good, Apogee I did not feel their $ met the product and RME was out of my $ range
There is alot out there and do due dilegence as now return policies are tight as any software that comes with a audio interface can cause return issues
(was not always like that but piracy changed things)
best of luck
Use the web and there is tons of info
ambienttales