I don't think those will work. I have one of those and it's way to small. Think of something in size inbetween a Desert Eagle and a Beretta, give or take.
There are a couple guys over at CT.N who have made runs of these, and they are absolutly fantastic props! One has been molded to have electronics installed (lights, ect) and a solid one, though it's been proven that you can modify the solid one to hold electronics and it still holds together right and true. Search for "torso_boy" and "p_trax" here:
http://clonetroopers.net/
Just remember no want to buy threads, they are touchy about thingsl ike that. You can PM them about one though. They usually run about $100, but it's well worth it. I wish I had one of those babies, then I could really freak out the highway cops :lol (j/k vode, the cops are my friends8))