Considering the fact that you will be tracking live instruments and vocals... I would highly recommend buying MBox2 from digidesign. It comes with a pretty loaded version of ProTools which is ideal for tracking, mixing and a bit of mastering as well. The majority of plug-ins for ProTools are EQs, Compressors, Delays, Reverbs, etc... ProTools DOES NOT support too many midi instrument plug ins. But since you are recording live instruments this should be perfect for you.
You can get a nice MBox2 bundle for around $700, maybe even less. Good luck
