I, and alot of others in the MOC use the JT's, solid as a rock, well almost anyway. I really think you need something on the rear also as that seems to be where a lot of sway comes from. Perhaps mounting the JT's a little further inboard would work. I don't know what a sliding bumper is so not sure what could be offered. MorRyde makes a set of stabilizers similar to the JTs. You might check them out at
www.morryde.com.