hi, im a regular forum member and i may have just the place for you.
A friend of mine is in the process of building a track on private land, with proper jumps, burms etc. Mainly designed for full size mx.
The track is based in hartlepool, near seaton carew.
Once construction is finished, currently in the process of roping it up i will post further details as we could do with spreading the word and getting people over there