In addition to their popular seat kits, Seat Concepts is now offering a complete bolt-on seat for the 2008+ Yamaha WR250R and WR250X which consists of their foam and seat cover installed on a Spiral seat pan. The seat installs on your bike in a matter of seconds using the OEM mounting points (2 bolts). Fit and finish is top notch and the comfort level on these seats is great.
I've been riding with Seat Concepts seats on my WR250R (and my WR250X) for the last few summers. I run the low foam version, so not only does it help me with the bikes tall seat height, but the seat is also much more comfortable than the OEM seat thanks to a wider seating surface and slightly softer foam. I've done several 250+ mile days with no issues... couldn't say the same thing for the stock seat!
NOTE: Seat Concepts still offers their seat kits if you want to save some money and just use your stock seat pan to install their foam and cover (see "Seat Kit" link below).