Re: sideshow bodies
Chakaman makes a good point. Alpha Toys released their "HT"'esque bodies an they retail for $15-$25. The come in Narrow Shoulder and Broad Shoulder, you'd want to go w/ Narrow shoulder. It may take a lil' modding, but it'll work. I used a HT Narrow Shoulder, w/ forearms from a HT Slim, on my Boba Fett. Made the figure so much better.
Kumik, about $25 as well, also makes a reasonably priced foundation body as well. They fall somewhat into the mediocre category in my opinion. I bought a couple an used them on some recent military customs. They work, but something just feels off about'em, and the skin tone is horrendous. Finding a HS to match is almost impossible, but hey, if they're going to be covered entirely in armor. I guess skin tone doesn't really matter. It would take some work to get the armor to sit comfortably though, having a Dremel on hand always helps.
As for tightening joints I stick w/ the old Super Glue or Fabri-Tac (takes much longer) methods. Not too comfortable using these methods, one screw up an you have an immovable joint, but it works. There's also taking the ball-socket off the bottom of a HT TT and gluing it to the bottom of the SSC Prometheus. I have a lot of broken bodies around, so I actually did this w/ my Darth Maul and he's pretty steady on his feet. Essentially what you have is the standard SSC Pro w/ HT ball-socket joints glued over the standard peg insertion joints. Then you can just pop in a HT (or similar brand) double-ended ball joint, and add you standard HT feet. Makes the figure a lil' taller, but that's just another suggestion.
Whew!! Sorry if I rambled on for so long.
Have fun modding your Clones though, can't wait to see the results.