The tires are whats going to cause failure problem, need to scale down to a lighter wheel and tire set.
These are 5" tall and weight considerably less and will help prolong trans and axle failures.
Example;
http://www.imexrc.com/servlet/the-28...-T-TIRE/Detail
Other than that your build looks like a lot of fun ! ! !
Shocks; 1/8 scale buggy shocks will serve well providing they are not to long.Edit(will require the softest spring availble due to being designed for a buggy that weighs twice the Pede does)
Like these ?
http://cgi.ebay.com/DURATAX-RAZE-FRO...item27aa75b2b2
http://cgi.ebay.com/LOSI-8IGHT-2-0-1...item414a17ec2c
http://cgi.ebay.com/NEW-OFNA-ULTRA-L...item20adee565d