I like the ofna lx front shocks with yellow springs for the rear of the crt.5. I just trimmed 1 coil off the spring to get the ride height correct. I ran a l can and a 3s, so my truck was heavier than some.
I use Mugen front shocks on the rear and it's a perfect fit, I just had to dremel the ball edges a bit to fit in the a-arm. So, whatever is around that length should fit. Be careful though, if you get "big bores", the bore diameter may be too big to clear the upper turnbuckle.
BTW: I would look at some ebay chopshops for a set of new shocks, probably be quite a bit cheaper.
Eric,
Go for the ofna lx one shocks that everyone is suggesting. They are cheap and work very well. The 13mm bore is perfect for the crt.5. I would say its safe to assume a good 80% of us use those exact shocks ever since go-ride posted the shock mod in this forum. I have no complaints with them.
There's two sides to every schwartz, he got the up side and I got the down side.