Student Loan Consolidation- benefits and good companies to do it through?

I have roughly $68,000 in private loans at a variable rate (currently 6.15%) and an extra $15,000 in federal loans at a rate of 4.15%. Right now my monthly payment is about $800. I'm able to pay it, but obviously it's very high and would like to decrease it if possible. I see a ton of places offering to consolidate, but don't know of one that won't try to screw you over. Also, is a good time to do it now, wait a little bit or what?