We definitely want the ability to download music. A similar game that could do this (like Guitar Hero World Tour?) would be fine. Also, we're interested in perks these game systems have (e.g. Blue Ray player), though that's not the most important thing.
I've heard that the 3 platforms that support Rock Band are the X-Box, PS3, and Wii. I heard the X-Box is the cheapest, but we need a hard drive to download songs, and a Wii is cheaper than an X-Box with a hard drive.
Do we want Rock Band 1 or 2? Also, is there some deal on getting 2 guitars, a drum, and a mic?