Another vote for the Pegasus Q 462, probably the best entry level flexwing ever built. A 503 Raven is a very close second. Both are available for less than £4k and although the 503 engines drink a bit more, both will have you flying for less than £12ph in fuel. The Q will be nearer half this, at mid 50s and a max straight and level of around 70mph.
Jay's school is highly recommended and another good school near you is at Enstone. Its run by Geoff Weighall, ex Chairman of the BMAA.
With spiralling petrol prices, microlight flying is becoming very popular.