A cheap 32GB CF card is not going to have anywhere close to even half the performance of an SSD. By the time you shell out enough money to get cards that perform well, you might as well have bought the SSD and saved yourself a lot of hassle.
This OCZ Vertex LE has the SF1500 which is supposedly an even better controller and comes with 28% over-provisioning and is designed for enterprise systems. It shows very well against It's more expensive brother as can be seen in this review
Most CF cards that aren't specifically industrial grade (the terminology is 'Fixed Disk' can't be booted in an array configuration of any kind. This includes those that can be formatted as either fixed or removable. It's really quite the pain getting any kind of OS installed on them, array or not.
TRIM doesn't really appear to make all that big a difference in the CF drive's performance. I don't know why this is, since it is supposed to substantially impact long-term performance.
I suggest just going with an SSD if you want to try a RAID config.
I've setup several laptops and media centers with 266x CF drives. Provided that you use tools like SSDTweaker, Junctions, RAMDisk and Flashfire, you'll notice a substantial improvement over traditional hard drives. TRIM might not be essential.