There's a guy on The Samba who has developed a kit  with all the needed parts to install lifting shocks on your poptop.  He seems to have done a good amount of trial and error and research before settling on the kit(s) he offers now.

There's a regular duty kit for tops with no racks/boxes/kayaks etc., and a heavy duty kit for tops that do have some stuff up there.

People have reported being able to lift the top with as little as two fingers!  Closing the top is supposed to be a bit of a pull down, but nothing difficult.

I haven't purchased a kit yet, but have been pondering it.
I believe he charges $85 for the kit, which doesn't seem unreasonable to me to get all the pieces that actually work!

http://www.thesamba.com/vw/forum/viewtopic.php?p=2847737#2847737