I like those guys but one thing you have to remember is they have to get the parts and then they send them to you so it can take a while to get your stuff. Here is another web site with some good prices and rates as one of my favorites http://www.midwestactioncycle.com/ 
Midwest Action is great for OEM parts and expert customer service. I use them alot and pay a portion of the overhead there. They have most OEM parts in stock, but they also gather aftermarket parts and sometimes backorder out of stock items. Motosport Outlet is the best for after-market upgades and no Ship and handling charges for purchases over $100. They also have free 2-day shipping, so you almost always get everything three days after the order is made. Thats important to me, because after the order, I'm watchin for the boxes at the door like a freak.....

Between the two of them they have had everything I've needed for my bikes.
Example; Motosport has that top-end kit for your 250 w/ wiseco piston for only $130.