If you have £40k to spend, look for an aircraft in the £30k price range, so you'll have some extra money left over to feed and care for it. Every airplane is a compromise. Some do better than other at some things - no type is perfect. It's up to you to define your most common "mission" and buy to suit. Remember that the fact that you own a plane does not mean that you can't rent something else (more seats) if you need it from time to time. I loved flying the RV-4, agile, nicely harmonized, but they're not very roomy, so less than ideal for overnight touring with a passenger. Cessnas do what it says on the box - none of it particularly well, but easy and economical to maintain for a certified type. Similarly Piper PA-28 series, though I would be very cautious about parts availability for ongoing maintenance. Fabric aircraft can be charming, if the fabric is in good shape, and you can hangar it. Taildraggers will build your flying skills better and faster than flying tricycle.
Aerobatic is nice to aspire to, but most aerobatic planes are otherwise an compromise. The 150 Aerobat is a very modest aerobatic performer, though if you can fly decent aerobatics in it, you're a better than average aerobatic pilot! I would think a Citabria ("airbatic" backwards) is a nice choice, if the particular plane is in good shape. Otherwise, excluding loops, rolls, and spins, any type can be "maneuvered" for fun and proficiency. Steep turns, stalls and chandelles are fun.
Buy the plane you can really afford to operate - so you fly it lots! If you're worried about the operating cost, and not flying it, why'd you buy it? Airplanes are no longer an investment - buy them to fly them, your return for ownership is availability, and not paying someone else a profit on operating hours. Do not expect a plane to appreciate. It will never be worth nothing, but rationalize that your return was hundreds of fun flying hours, 'cause it won't be lots of money when you sell it!