if you want it to stay waterproof after you kill the titans and also want brushless power (but not quite the same)
google "kershaw designs"
they have a large single motor kit that will poop all over the titans and you can use only one of their motors if you want.
the biggest weak point of stock e-revo would have to be the rear toe links!!
go for an RPM true track system.
the E-maxx and E-savage both are proper "trucks" they roll over all the time, have 8 shocks and look cool. but the E-maxx has weak bulkheads and the E-savage has a weak transmission. the savage flux has the tranny fixed but the brushless E-maxx about to hit the shelves does not have anything fixed
if you want waterproofness to hang around then go for some 7 cell large nimh packs.
the stock ESC is fine with them and they get pretty good speed on the kershaw 970 motor. (make sure you break in the motor as it is brushed)
but WHEN you upgrade to brushless, expect for get some good quality lipo's while you are going as the rule goes, never run nimh in big brushless trucks (4s 5000mah 20c and above usually)
beware of the 2nd hand bit...it might look nice in the pics, ive done that before too! in that 6 times the titans could be dead. he may have jumped it and pulled off a suspension rod end, this can be screwed back into place but severely weakens it so next time you jump it they pull out a lot easier!
as for the tyres looking good....get used to that, stock E-revo tyres NEVER EVER EVER EVER WARE OUT!!!! they grip about as good as a possum on water too. they actually grip a little bit better if you do a burnout with them (but that is not recomended as it is super hard on your system)
that should get the ball rolling, the rest should flood in, expect a post from mrcrash soon
btw are you from aussie?
shaun