How are roll-bars typically made/purchased?

[jtoomasson at yahoo.com (Jeff Toomasson)]

Most likely I'm going to have to have a simple roll-bar setup when I do my ragtop to prevent undue stress to the roof from chassis flexion.

Honnold mentioned that he got a "Autopower" setup, but I don't get anything when search for that in Yahoo. Went to the .org for various links to racing sites and got nothing (BSI, Shine...). I don't see any at some of the tuners' sites I've checked either...

Are they typically custom-made? Is there a minimum tubing gauge that must be observed? I'm assuming it's better to have them bolted in as opposed to welded...

Also, should I have it installed when I have the car painted? Or do it after?

Thanks in advance!  Jeff