First a correction to what I said earlier. MPF puts the time your VSP is based on on your seperation orders, not your DD214. Sorry. It goes in block 21b.

In regards to HOS, VSPers with at least 8 years of continuous active duty with no break in service greater than 90 days are entitled to HOS vs HOR. The full details of HOS are outlined in the JFTR (if you are having trouble sleeping you can download it and read it) but the jist is:
1. You can move anywhere you want, not just back to where you entered from and they won't charge you the difference
2. You get 365 days to complete your move versus 180. So if your stuff is still in storage they can't charge you until a year from your DOS.

There was a matrix on the AFPC website entitled "Services & Benefits Available Under Force Shaping" This was where it was laid out, however, I can no longer find it with all the FY 08 stuff on there now. It should still apply though, especially if you were 07. Keep looking it should be there somewhere.