I'm looking for a skiplate for my '02 YZ250 that offers protection for the frame rails, as well as the ignition cover and water pump. I installed a Yamaha enduro skidplate on my WR426F, which was a really nice product (perfect fit and very well constructed), but all they have for the YZ250 are glide plates. I'll be getting into some nasty rock gardens, so it's got to be beefy.
Utah Sport Cycle makes some pretty good skid plates, they even had one for a KX100 and I looked wide and far for that one. http://www.utahsportcycle.com
Moose and White Brother also make good plates, check with MX South.
Just received a skid plate for my KX500 last week from Utah Sport Cycle. Good price, excellent construction, fits well and has excellent side coverage. I recommend them.
I put an E Line Accessories skid plate on mine. If you are looking to go carbon fiber and willing to shell out the extra money. I strongly recommend this product. The protection is great. You will not be disappointed. Just my .02 Good Luck!