We looked at these some time ago. Although they are "Flash" their documentation talks about them being ECC and other protections they've put into them.
We never actually got them (we were looking more at disk array solutions and only looked at these cards for a possible proof of concept we decided not to do).
http://www.ramsan.com/products/ramsan-10.asp
You might also consider actually using an external array for your storage instead of in the box as many of those have their own cache and caching methodologies that can help performance quite a bit. The above company sells some of those as well (including some that are based on DRAM rather than Flash). We use EMC Clariion and DMX for our big storage needs and the caching helps quite a bit. Also with external arrays you can often do things like RAID 10 that might not be available on in the server RAID controllers.