I'm thinking 331 to 98, and then 98 to whatever the little cut-off road by the Camp Creek Golf Course. If you took the Mid-Bay Bridge, you would need to jump off I-10 at Crestview, 85 South to Niceville, 20 East to White Point Rd, south across the Mid-Bay ($2.50 please), east on 98 about thirty miles. Good news is that it is four-laned all the way; bad news is you have the potential to run into major traffic in Crestview, Niceville/Bluewater Bay AND Destin.
Another possibility is I-10 east to Hwy 81 (ten miles east of 331). South on 81 to 20, east on 20 six miles to Hwy 79, 79 south to 98 in Panama City Beach, right on 98, and left on 30-A to Seacrest. There is very little traffic on 81.