I'd also like to congratulate you on the amazing progress you've made.
In my opinion, most of the exercises you can do with a home gym can be done with dumbbells and a stability ball. I have a gym membership, but the only lifting equipment I use is the squat machine. For everything else (presses, butterflies, hyperextension, etc.) I use the ball. I had gotten a few videos to learn the proper methods and then adapted my own workout routine. A rubber ball is a lot less expensive than a home gym.
If you're set on a home gym, I personally prefer the feel of free weights. I've used a machine with some rubber band-like contraptions and the movements felt awkward and unnatural. I've seen the bowflex commercials and I've always felt skeptical, although I've never tried one.
Happy hunting.