I just purchased and assembled the K-20 keyboard keyer from K1EL. It was an easy build and this was my first project. Anyway, you supply a computer keyboard with a PS/2 plug and it does the rest and can run on a 9 volt battery. A lot cheaper than the commercially produced keyers, and a whole lot of features. As for the readers, there are a few decent decoders out there as shareware, and I have messed around with them a little, and I think CW Get is the best one I've used. I agree with the previous posts that at some point, your ears will do the job just fine, and I use mine mainly to practice my sending on straight keys, bugs, paddles, etc., as they are very honest and let me know how my characters look to the computer.
Anyway, I think the K-20 is a can't miss for a keyboard keyer, and should be very useful in contests, and the like.
The page is www.k1el.com
Hope this helps, and 73