Straick

I run my Revo in the snow all the time, and during the summer in sand. If you will be running in sand a lot, a hardened spur and clutchbell combo will be your best friends. The spur won't wear out like the stock one does. Just have to have your slipper set properly. The only other "mandatory" part will be a good quality 2 or 3 stage air filter. The stock Traxxas ones are garbage if you're running in sand. I only oil the inner foam filter on mine and keep the outer one dry. The outer one catches the larger dirt and a lot of the sand, and the inner the finer debris. I also carry a portable air tank with blow gun to blow out the prefilter, and the truck when done in sand.
Biggest piece of advice, be ready for some major cleanup of the truck and where ever you put it to transport it. After a snow run, I set my truck in the shower with a portable fan forced heater blowing on it without the body to force dry/melt. The sand will pack in between the body and chassis, but if your jump it every now and then, the sand underneath will get knocked off of the truck. Still have to replace bearings every year or two even with hitting them with a penetrant grease after all's dry.
The only real wear I can find on it so far from the hard running for several years is that the driveshafts all need to be rebuilt soon. The universal in them are getting sloppy.