Rear 4-links: Battle Version vs. T3

[Yonzie]

I'm looking at upgraded 4-links and panhard rod, but a few questions have come to mind:
When lowering, how low can one go before needing to upgrade?
Which one is the best choice? Battle Version or Techno Toy Tuning?
The BV stuff is $510 and the T3 stuff is $449 with a $25 package discount which I expect Battle Version would do as well. The difference then amounts to $36, which is less than it costs to take the GF to a movie (and less than 10% of the whole price), so the difference is small enough to not matter.
On the face of it, T3's stuff looks better, but Battle Version has a pretty good reputation...
What do you think?

http://www.battleversion.com/AE86rear.htm
http://www.technotoytuning.com/t3_site_p...links.html
http://www.technotoytuning.com/t3_site_p...nhard.html