It depends. Are you planning to record live drums or do you plan on using a drum machine?
If you are using a drum machine(or don't care about mixing the drums individually perfect) Then I'd go for an M-Box 2 by digidesign. It has two inputs and runs off protools., and it's only about three to four hundred.
If you are recording live drums (which is what we do) then I'd go with the 003 rack by again digidesign(again protools). It has eight inputs which will be enough for a demo.
A good set of drum mics is necessary if recording drums, and an sm57 for guitars. Vocals can be done on just about anything but ofcourse they have specific ones for that as well. Hope this helps.
