Go with the 8xSSD in raid0. But remember that Raid 0 is fast, but fragile - and gets more risk with every drive added to it.
I've been running my main video editing rig with 4x64 OCZ drives for over a year. Its holds just OS, programs, and the temp store for Vegas. I was paranoid when I set it up, so I take an automated Ghost image of it every week. Fiugre I could lose a week of OS/programs with no problem. A couple of weeks ago one of the SSDs when silent any my machine was off-line. Only took about an hour to remove the bad drive, set it back up as a 3x64 Raid 0 and restore the last image. Back in business, fast as ever. OCZ took the warrenty RMA and got me a new disk in about two weeks and in just under another hour all was back to normal.
Fast raids of SSDs are awesome.
Fast raids of SSDs with good backup are even better...