I've used ss5800 with TLT axles before with no problems,kind of a mini Monster Jam type rig with 4 wheel steering.20mph is quite fast for one.For a crawler the small outrunners with a mamba esc seem to be the ticket.
http://www.rccrawler.com/forum/showt...ight=brushless
I'm thinking of building a scale trail rig too,i've got loads of TLT axle parts,i want chassis rails and leaf springs.
Have you seen this
http://forums.radiocontrolzone.com/s...d.php?t=218243
should be out in the next month or so,i'm seriously considering one.