Emu XL-7 & MP-7 User's Group

hey guys, again sooo sorry about the noobness here, feel free to
scream at me! im about to pick up a keyboard next week to use instead
of the pads, what should i be looking for? i would like a cheap one
cuss its only for using the keys and not effects or intruments ect,
can i use any keyboard? which one does it have to have? midi in or
out? im not sure :S
  thnks again guys/girls
really appriciate the help on these groups!