[tevake]

The spitfire is a small step up from the sprites and midgets but still hard pressed to keep up with modern highway traffic. Unless you have lots of twisty back roads, and I think you may have. I would consider a TR 6 or MG B. As a more well suited car to use these days.
I do really like the styling of the Spitfire, even more the MG A. But with their low cut door line they don't offer even the illusion of driver protection. Funny how that never bothered me at the time.

As to unreliability, I once bought an MG A in Fla and within a week headed out for Sesttle in mid winter. Made it with no problems. Had lots of fun with Brittish cars in the day.

Cheers Richard