"Best" depends upon your requied application. If speed is your peference then you can raid 1 as many dives as you like. One of the beauties of SSDs is that they scale almost 100% within bus limitations. What this means is that you will hit the cap fo onboard contollers with 2-3 SSDs on the read side and you will only see gains with a dedicated contoller.

To be honest I would not really look at using Raid 0 for SSDs as its strength is redundancy whereas SSDs strength is performance. Regularly backups to a regular hard drive would probably be more cost effective.

If you want pure speed, then you can get a high spec areca controller and hook up 8-10 SSDs and get 800MB/s throughput. Alternatively, a product called Ioxtreme is due to be released Q1 next year which looks pretty snazzy.

Cheers