KC,
the new hybrids of Bermuda grass tolerate the drought much better, but for my runway I am putting in an irrgation well. I am flying my turbine off the Bermuda grass, but it is not fully grown in yet. I bought a golf green mower (Toromaster 300 Reel mower) to keep it cut down. It will shave it down to a 1/4 inch and make it look like Astroturf. The Bahai grass is aggravating, and can get out of control pretty quickly.
Asphalt is better, but it is expensive, and requires to much up keep for my place.
Between the two choice you have given, mine would be the Bermuda.
Tommy