Ill be honest, this close to the holiday season i recommend you hold onto your money, you will probably be able to get a 256gig model for what your looking to spend. If your motherboard supports it, i recommend stripe raiding 2 ssds together. I have 2 x ocz vertex 3 120gig ssds in a stripe and its giving me over 1 gig read and write speeds. I have yet to ever come across a system as smooth and responsive as mine.
Remember that a newer generation ssd is only going to give you the high speeds if you connect it to a sata 3 port.