I'm planning on turning my xB into a giant tool box and I wanted to know if anybody knows of any suspension upgrades that are built to hold allot of extra weight. Like an extra 1500 lbs. If there is such thing.

 

Naturally, the site won't let me link directly to the part for the xB, but it's simple enough to find: http://www.airliftcompany.com/online_catalog.html

It's essentially an inflatable helper spring that fits inside your rear coil spring.

I used to have air shocks on the rear of an S10 I had in college, and they were great. Without them, the back end would practically drag on the ground if you loaded it with empty cans, but at 100psi, I could (and sometimes did) load it like crazy with cinder blocks, wood, furniture, etc. You just have to get used to the wacky handling with a super-stiff rear end.