9.6v is what most transmitters run at, so you can probably find a pack made for transmitters in the BST forums here or on Ebay. Do understand that you get what you pay for though. Not all cells are equal, and the good ones will cost $2-$3 each. Cheap ones don't last as long, don't put out as much current, aren't as tolerant of abuse (and flying is abusive) and don't hold charge as well. The best NimH cells on the market are Sanyo Eneloops. All Sanyos are good, and most guys flying more expensive planes won't use anything else, myself included.
Since you're asking for advice, I'll offer than cheap batteries offer no cost savings whatsoever. You'll replace them sooner than good batteries, and they will occasionally cost you an airplane.