Oh, now a basic home isn't good enough for you. Let me guess, it needs a swimming pool, three car garage, and a finished basement, too.
Yes, $20K down will get you a standard 3 bedroom home. You want to have a McMansion which is unaffordable for 99% of the American public.
You can buy a 3BR home for $130K in Oklahoma City, so yes putting $20K down will absolutely secure you a home.