Re taxes - the 3 counties are almost equal.
Re deed restrictions - Lake County is the most lenient e.g. you may put lawn art on your front lawn - the other counties restrict that.
Other differences include the impact fees and huge bond you will pay south of 466 (in the newer parts of TV). In many cases it is 3 & 4 times larger than those originally charged north of 466. Versus buying a used home north of 466 - either Sumter or Marion counties. In many cases the bond has already been paid and there are no impact fees. Could mean a difference of $15 - 35,000. I strongly urge you to check out the "used" homes before you decide.
This is an excellent time to buy either way - prices have dropped in this slow market. The one thing alot of people usually regret is buying too small a house the first time. Also, buying a home with less than a 2-car garage. Being centrally located, with good access to both squares is recommended. Good luck.