Long Term Rental for Relocation

Family of 5 looking for a long term lease. We are relocating from Ohio around November 1st to help care for my father who lives in the Freeport area. We have secured a vacation rental in Grayton Beach for the month of November, but would need to find a long term lease shortly after our arrival, and from my understanding the kids would attend Bay Elementary and South Walton High School. We would like to stay in this general area so we do not have to change schools again.

I am an insurance agent, and my fiance is a Marine Mechanic. We do have some great employment opportunities lined up at this point, however I am finding in my online search that the cost of rent is much higher than what we are used to in Ohio. We currently pay $600/month for a 4 bedroom 1600SF single family home in a very safe, quiet neighborhood on Lake Erie. Most of the property managers I have spoken with really want nothing to do with helping us until we are already down there, and due to some credit problems when the economy bottomed we were one of the many unfortunate families affected by foreclosure in Ohio. My worries is that we will get down there & not find an affordable long term rental and end up having to come back to Ohio right away. Any advice is greatly appreciated and welcomed.