Duncan at Automotive Unlimited and John Taylor both seem to source an unbelievable amount of mint cars.
I think £16K should get you a nice example, just make sure you do your homework and take your time.
I'm not too handy with a spanner myself so I took advantage of any help that I could get. A number of very knowledgeable people on here looked at cars with me or on my behalf.
That £16.5K Aubergine one on here seems a very nice car for the money in my opinion.