I'd say better do some more research before you spend your money. There are several options out there.
For example, I am considering the emagic Gold Production Kit (
http://www.emagic.de/products/collections/emi62m.php?lang=EN ). It has the EMI 6|2m USB interface, Logic Gold and a couple audio units (e-piano, b3 organ, sampler). It's a good deal, actually, since the USB interface and Logic Gold alone cost a lot more than the package (can get the package for 600 here). The USB interface has
6 inputs and 2 outputs as well as MIDI.
You can get a cheaper Logic Audio collection, but without the USB interface.
There's also a package from Steinberg that retails for 279,- here, featuring Cubase SE and a couple VST instruments, but you'd need to get a USB interface yourself. E.g the Terratec Phase 26 (300,-; 5+1 surround outputs, stereo in, stereo phono in, mono mic in, midi) or the M-Audio Quattro USB (300,-; 4ins/4outs, MIDI).
Note that I didn't try any of these. I'm just mentioning them since I'm in the same boat (researching for audio hw/sw to buy).