I have my boat out on Joe Pool Lake in Grapevine. The deal on Craig's list is GREAT! Even if you don't use the boards often, $200 for two w/spares is exceptional.
We have a "One design" windsurfer on the dock with our boat and use it all the time. The winds we've been having these past few weeks have been a blast. With a harness, the smaller sails and the small waves the board hops right up on plane and flies.. 20+ knots steady wind is a real thrill. A "long board" (the BIC) will work in all conditions..even the relative calm days. A short board has less displacement so it will need more wind... but with the choices presented with this deal, I think you've got money in the bank.
Great fun, steep learning curve, hard on the body, especially when feeling your way into it. Taught me a lot about trim, balance, and points of sail -- tho the adjustments aren't as refined as a sailboat's. Also, throwing a rooster tail during a jibe is just fun.
Harness & PFD mandatory. Water shoes advised. If your water is cold, wear one wetsuit warmer than you think you need. The apparent wind on a sailboard will strip the heat right out of you. Oy, they are a riot.