I would recommend taking a good look at what you expect from the boat and how you want to sail it, and make your decision based on that. Rather than the width of the boat on the trailer.
I used to tow a SOL Cat 18, 7'11" wide with a Toyota Carina, about the size of today's Corolla and I know what you are talking about. Made the trip from Long Island down to New Jersey, (for Class Racing) going over the Outer Crossings Bridge, which only had 8' wide lanes right up to the guard rails. Used to sweat bullets, but once I got it in the water, it was well worth it.
If you can, try to sail both.