SSD Raid 0 stripe size for windows 7

Depends on your data. The larger the most commonly used data file the larger the stripe generally.

For Win 7 and general office type stuff use a smaller stripe it gives better speed and creates less slack space, so go with 64k. If you do a lot of large file work, like video transfers, then a large stripe is best. I use a 512k stripe on my raid 6 video storage array and a 64k stripe on my c drive.