5 Years, Ramble

Okay if someone would have told us this tour was going to be 5 years I don't think we would have applied, but Everything Happens For A Reason!
So we have been thinking about purchasing a house. If anyone has advice on this please spill.
Jacob will be in finishing 7th grade when we leave here, which means he will finish school at North Bay then have to go Over The Bridge to a different school for 7th, so he will get to meet more friends and maybe loses friends again. But that is 4.5 years from now. Maybe Biloxi will build a Junior High Over in North Bay Area due to the fact there are houses going up everywhere.
I know they asking folks to sign a petition to have the schools re-annexed due to tons of new developments.
Connor will be in 3rd grade. So at the rate we are going we move from here Jun 2011. Mike will have 14 years in. Jacob will be going into 8th grade and Connor 4th when we go to our next duty station, that is if there is a next duty station.
Back to this purchasing a house, can you do it with no money down, no closing cost, if so how??? Spill!!!
Thanks for reading my ramblings