I would say weigh out the +'s and -'s of each option. I'm sure you should be able to get the 8500/yr subsidized federal which you should definitely do b/c there is no interest until you get out. On the other options consider what the interest rates are, if they are fixed - i think the fed fixed rate is like 6.7% now and the last chance to consolodate at a lower rate was this past july -(I would personally rather go with a fixed rather than ajustible even if the fixed were a few points higher b/c interest is likely to go up in the next few yrs [just heard a labor rpt that wages have exceeded inflation in growth by about 2 points and we are likely on the verge of democratic congressional takeover] but you should do your own research and make that call on the whole interest rate speculation thing, just know that you can predict what happens with fixed, whereas you cannot with variable)
Thus, you should weigh in consideration every factor you can think of: rates, repayment plans (many gov't plans give you a grace period after you graduate, although I believe interest still begins to accrue (on the in school int. free subsidized ones - unsubs will have already been accruing) but don't quote me on that. Also figure out who your lenders will be/are and use discretion on which would likely be the best to work with if payment complications were to arise. Ultimately it may be a good idea to try to get rid of some of your pvt loans for federal, but since you have likely had them for a couple years they likely originated when interest rates were lower and thus despite the many incentives to federal loans you may still be better off with your pvt ones. So, yeah, sorry bout the long post...Just weigh your options and if you are ever uncertain make sure you get in touch with a financial consultant (you can look in the phone book for one in your city, or perhaps your bank may be able to recommend options, you could also try to talk to a finance professor at your university.
J