[adam]

Oooooooooooooooooooh, single instruments, my apologies. You DJ with vinyl, yes? So you know you can often fudge it with EQs and filters. You can't get perfect isolation, but sometimes those imperfections work really well. Assuming you want better isolation than that, a lot of magazines review sample CDs, I'd try and locate some of them online and find something that suits you.