Mr. Rocket - I have 4 crawlers. (You'll probably need to open an account on rccrawler.com to view most of these pics...)
1 - 1.9 VX 1/10 scale hard body TLT-1 (Work in progress because the guy who sold me the VX body lied about it's dimensions. I started an exo-cage and then moved on to my 2.2 crawler. No pics yet.)
2 - 2.2 HPI Wheely King tuber of my own design using 3/16" brake line as the cage - Works pretty well for a scaler actually!
3 - 3.2 Kyosho Mad Force (Rock N' Rat Rod) (Using a drill motor with a 2-speed planetary trans switched by a servo. Also work in progress.)
4 - 40-Series CEN Nemesis Super Class (all aluminum with a wacky gizmoiness concept - stopped when I went over $1000 in parts.)

Here is the craziest crawler I think I have ever seen: Intense

rccrawler.com is the big site - but there are others to peruse. We have two local sites here in Utah. There are some UK sites I believe as well. Check out these vendors:
http://www.rc4wdstore.com/2/
http://rcpcrawlers.com/home.php
http://www.montanascaledesigns.com/shop/index.php
http://www.tcscrawlers.com/

I think most ship over seas...

The best bang for the buck, IMO, is the Venom Creeper