I bought mine off Ian and it is a very good quality unit - there are possibly a few cheaper versions out there but the one he sells is very nice.
Lots of CR's on the forum - they are a very good car (I may be biased) having won King cobra, queen cobra, shelbyfest etc. There are some worthwhile mods you can make, especially the rear suspension toe arm mod - virtually eliminates any rear bump steer. Makes a huge difference. Aussie Mike can make you up a set if he's not too busy
If you want to see some quality square tube CR builds, check out Mando's, Mikes, or PhilM's gallery's.
Cheers