One option is to get a CRT.5 and the RC-Monster extended chassis. When used with wide-offset 1/10 truck wheels and truck tires, the extended CRT.5 is something like 1/11 scale.
Kyosho has recently introduced their new line of 1/10 4wd nitro buggy/truggy that appears to be a good candidate for conversion, but they aren't out yet.
http://kyosho.com/eng/products/rc/de...duct_id=102633
http://kyosho.com/eng/products/rc/de...duct_id=102632
SH Z-Car, Custom Crawler, 8s Savage,
12s XTM XLB 1/7 buggy,
4wd 4-link rear/IFS Pro4 truck,
Custom Hyper 10 Short Course,
Belt-Drive Mammoth ST 1/8 truggy, 4s 17.5 MM Pro HPI Blitz