It would seem the Karma has been discontinued, so unless you can find a store that still has them in stock, are willing to buy used, or can find "new old stock", you might be out of luck.
However, I think the general consensus on the forum is that any of the DAPs talked about frequently here are worthy of consideration and it's largely a matter of preference. The Creative, Apple, iAudio, Rio and iRiver players are all highly thought of. The best thing to do is combine auditions (if possible) with careful thought to the price, feature sets and usability of each DAP.