Anyone have an idea of how many dwellings are in the oklahoma city metro area? When I say dwellings I mean homes AND apartments.

Google is your friend

EWAG, based on estimated population of OKC and 20% vacancy rate

800K, give or take

You can get Multi-family summary report from Price-Edwards (http://www.priceedwards.com/) - Look for Market Trends -> Download Current Market Summaries - requires you join but not a big deal.

There are other sites where you can find estimates of housing trends but I don't have the URLs handy right this moment.

You might try City-Data too at:
Oklahoma City, OK Houses, Apartments, Cars, Mortgage Status, and Residents Info (http://www.city-data.com/housing/houses-Oklahoma-City-Oklahoma.html)