Stay away from Wiseco!!! rebuilt my KX250 last year with all internal wiseco parts. I thought with wiseco's reputation for their products, mainly pistons, that there bottom end components would be great as well. However, at 38.1 hours from complete rebuild, the main bearings on the crank blew out and shredded my cylinder and piston. Wiseco pistons are great and I stand by them, but anything else they produce I would be very skeptical about. OEM, IMO, is always the way to go for engine components, especially the crank, rod, and bearings. I went with wiseco because of the price difference of the OEM crank, but in the end it would have saved me a lot of money to buy the OEM crank assembly.
Good stuff: Pro Taper contour bars, Pro taper pillow top grips, Easton 1-3/8" fat bars are awesome, pirelli mx extra tires are very durable and last the longest of tire I have run, pirelli mxms tires have great traction but didn't last more than three rides before chunking and losing knobs, Boyesen water pump with super impeller works great and dropped my engine temps by 12-15 degrees F, Maxima Castor 927 premix works awesome and smells great, Twin Air fliters hold up great and work well, Amsoil super tacky air filter oil is great, One indusries Carbon jersey and pants are comfortable and have held up to a year of abuse, Sunline multi-flex pivoting levers are life savers!, CYCRA plastics seem to be more durable than any other brands I have tried, V-Force 3 Reed system has worked well for me!, Dragon Vendetta moto goggles with laminated tear off's are very nice, Fox V2 helmet fits true to size and has lasted several years, RK x-ring chains!, Grip donuts work wellfor me and no blister to this day since using them, Thor moto gloves slip on's don't have a wrist strap and breath very well!, there is alot more, I;m just drawing a blank on the other stuff.
Bad Stuff: Renthal Kevlar grips are not worth the money, they tear just as easily as most other brands and look like crap after the first ride. Enjoy Graphics, the glue they use will not hold up and will delam after a few rides, make sure your graphics use 3M adhesive!. Kenda tires, did not hold up and were a pain in the a## to mount. Wiseco bottom end kit, blew out the bearings at less than 40 hrs. Tusk Gaskets are crap, go with OEM or maybe Cometic.