The disk setup really doesn't have any affect on gaming whatsoever, except that for the load time inbetween levels.
As far as setting up a RAID 0 setup... A couple of things to keep in mind.
1. Your performance will be affected by you file size and RAID stripe size. If you have a lot of large files or do video editing, a large stripe is preferable and vice versa for smaller files. The catch is that if you want change your stripe size, you lose all your data and have to re-install your OS and apps everytime. Is this something that you are willing to do to find the best stripe size for your application?
2. When using a 2 disk RAID 0 array, your reliability decreases by 100%. Since your data is effectively spread out across two disks, if one fails all of your data is lost. Since you are runnning a small business on this computer, if you go with a RAID 0 array, you might want to consider some sort of backup solution. Or even consider RAID 1, which provides redundancy, but no performance benefit. For a better explanation of the various RAID options. check
this out.
I'm not discouraging you from RAID in any way, but you should do some research first to know what you are getting into. I personally have a RAID 0 array and have been fairly pleased with the performance, but I also do not run a business or maintain any data that is of any consequence to anyone but me.