Good topic. The crappy cage in my CJ needs to be replaced very soon with something better designed to protect the rear seat. Can't decide if I should buy a JD2 and build it myself or just pay someone else to do it. By reading some of the prices on here so far, it sounds like it would be in the $1500-ish range to have it done. Pretty tempting...
I'm thinking 1 3/4" HREW will suit my needs just fine.
Talk to Dean at Bent Metal Customs, he's in Puyallup and does a really nice cage.