You have a great plan, and I hope it all works out. Excellent.
" If you can't afford the house you want then wait and save. DO NOT count on getting extra money or saying you can cut back on stuff for life. If you can't pay the payments on the money you have now DON'T DO IT!!! "
I got similar great advice from a shoe salesman. He said "Buy shoes that fit perfectly in the store." If they pinch you in the store, they will pinch you forever.
A house purchase is the same. If it pinches your budget now, it will pinch your budget forever.