congrats and hope you find new thigns about quads on this site
as for the rancher a good pipe would be good, just a slip-on such as an idx is good, i like the sounds of them, find a good air filter such as a k&n with an outerwears.
A good lift kit and some tires with rough tread patterns woulkd be good for mudding.
Also look into winches.
2008 Can Am DS450
PRM Baja Bumper and Skid
2007 Honda Rincon 680
Fuel Injected
ITP Mudlites
Hopefully some more goodies soon
1986 Honda ATC 250SX
Knobby tires all-round
otherwise.................... STOCK