I agree with the boys here, if the springs are right, you should not need tramp bars, they cause more problems than they fix.
Reverse eye springs with a reversed half leaf on top is a good start. Billies = good. Lowering blocks are a blight on humanity, they belong in the bin.
Forget about slippers etc, that is pure Group 4 stuff and you are talking 5 links, cutting up the floor pan and big $.
I run a panhard on my MK1 and swear by it. They stop the car winding up tension on the leaves coming out of corners and absolutely stop the tail wagging that causes. Very predictable and easy to drive on the throttle.
Its all fun until someone loses an eye....then its still fun but with less depth perception.
Cheers
Shaun B