Get the X-25M, they are popular and very good. A good storage drive is a samsung spinpoint...very fast! Western Digital are amazing but i guess you had some bad luck so no big deal. Since you don't want crossfire, then a 550Watt quality PSU or a 600watt will be good. If the price difference is tiny then don't worry about it.
I'd recommend against counting on being able to get an identical drive down the road for RAID0. Chances are, there will be a different model with different firmware out by the time you are ready to get a second drive. I'd suggest just getting the performance you want now and not worrying about it until the next generation comes out.
Also, TRIM and SMART are issues with SSDs in RAID. You don't want to exclude yourself from TRIM after you've done a lot of writes to the device.