Personally, I'd say to sell the TR6 and just use the MGB GT for a while. Let the finances settle.
As for Spridgets vs Spitfires, both are neat little cars with plenty of plusses for either. Make sure you can fit in a Spridget, they're a bit tight (though I fit reasonably well at 6'1"). Spitfires have more room. Neither car is fast, though they can be made fast with copious amounts of cash.
Less is more, Doug. Sell that TR6 and you've still got a nice classic to enjoy for a while. After some time your budget will heal and you could consider something else to play with.