Mark,
I received yesterday a second server having 16 drives bays. Just for a quick trial, I used 2 old 60GB SSD (a Kingston V300 and a ADATA SP900) to build a RAID0. To my surprise, my very pecky RAID controller (HP P410i) recognised them without a fuss (although as SATAII drives at 3Gb/s. A quick fio benchmark gives me 22000 random 4k read IOPS, more than my 5 146GB 10k SAS disks in RAID0). I moved my most frequently used index to this array and will try to do some benchmarks.
Knowing that SSDs based on SandForce-2281 controller are recognised by my server, I may buy a pair of bigger/newer ones to put my tables on.
Thanks!
Charles