Keyclone is worth far more than the 20$ you'll have to pay for it. It's the only one I've used, admittedly, but from what i've read, it's by far the best and easiest to use program there is. I jumped right into 5-boxing about 2 weeks ago with a FTL'ess setup, there was a little bit if a learning curve, but spend a few hours with it, read the tutorials, watch the amazing tutorial videos that Keyclone has on his website, and you'll be up and running in no time.

Happy Boxing!