I went from a 1.2 Punto to an NA Supra myself, after racking up just over three years no claims with the Punto. I had (and still have) no wish to kill myself, and jumping straight into a TT with no high powered/RWD/Turbo experience did not seem a good idea to me. I'm glad of this for a few reasons -
When I bought my first Supra I had absolutely no idea about anything car related (this was ~ a year ago), and while I took someone with me who 'knew' cars there were many things he did not pick up on.
The car I bought, turned out to be near enough a death trap (aka a 'dog'). It had three semi-seized calipers (one piston seized on each front caliper, and rear right seemed seized also), aftermarket wheels with unevenly worn tyres, a failing water pump and rad cap, and a fair bit of rust with a small amount of damage (hidden under the body kit). It's also had a poor 'spray over', with the paint flaking at the edges. It's cost me several thousand to put 'right' and I'm very lucky I didn't end up in a tree (or similar) while I was driving it in that condition (I believe an extra 100bhp with a turbo kick would have made this far more likely).
Ironically I only found out there was something wrong with the car due to buying another one () and finding it drove a lot better. I also took it straight to Chris Wilson for a full service, let him give it a once over, and did any preliminary maintenance he suggested (I will now do this with any car I buy).
I suggest you get to some club meets, get some passenger rides (on the road and track days), and if possible get some drives (even if gentle) of cars you know are set up correctly, so you know how a good one should feel. I would also get another year of no claims under your belt, because £3750 is insane no matter how you look at it (but it is up to you).
Good luck.