I agree with the BB7 recommendation on a budget.

Now, as to where to buy them? And you want to race on your LBS's team this summer? Hmmmm, let me think.....how about through your LBS?

If you ask their opinion/recommendation and then show up with discs purchased online or from another shop, then you will hurt your chances of being on that LBS's team.

Trust me, as a long time mechanic, we remember the customers who spend the extra change to suppor the shop. We also know (and remember well) those who waste our time by using us for info and then save $10 by buying somewhere else.

Here's a good tip to getting remembered by your shop in a good way. Buy the BB7's from them and then ask them to "show you" how to install them. Offer a pizza a 6-pack of microbrews as payment for the lesson.

You'll be heralded as "one of the good guys".