Just to reawaken this thread. I recently purchased an ipad and discovered that not only could I dropbox my mp3 files from my computer onto the ipad and thence into some very good mp3 player apps'; but having done that I only had to connect the sound orifice of the ipad to the rear sound input of my KN7000 and I had completely bypassed SD Cards etc with my backing tracks for my singers - see www.tributeartistes.com
Katrina you are it seems in much the same situation of providing backing for singers from time to time and this may be a better route for you than purchasing another laptop.