i doubt you will get much performance from using those CF cards in a Raid configuration. Even though they are solid state, their sustained transfer rate is much less than an actual hard drive. all you would be saving is power consumption.
here's an article on tom's that shows the typical transfer rate improvements of using a SATA CF adapter:http://www.tomshardware.com/reviews/accelerated-compact-flash,1100-6.html
just cuz you have an adapter doesn't mean the cards will perform at SATA speeds. as the article shows, they are barely faster than CF transfers with your typical USB2.0 reader.