http://www.rc-monster.com/forum/show...ghlight=redcat
http://www.rc-monster.com/forum/show...ghlight=redcat
http://www.rc-monster.com/forum/show...ghlight=redcat
http://www.rc-monster.com/forum/show...BL+1%2F5+scale
http://www.rc-monster.com/forum/show...BL+1%2F5+scale
http://www.rc-monster.com/forum/showthread.php?t=28084
http://www.rc-monster.com/forum/showthread.php?t=24325
http://www.rc-monster.com/forum/showthread.php?t=25755
A few threads with info & pictures for inspiration- many of the large 1/5 buggies and trucks are very similar so you can use similar motors, esc and batteries ( power output in watts being the key thing, then match the motor kv to the voltage for the desired speed ).
There are no simple conversion kits unfortunately, it will all need to be custom made.
You'll probably be best with a large motor, like the castle creations 1717 or a Neu 1527/ 22xx series, and maybe 6-8s lipo atleast. Esc will need to be something big, like a boat or plane esc designed for 8-12s lipo.