Well Ispent about 1hr 30 mins in PMT in Bristol, They were great and let me try a few basses. I decided that I preferred 4 to 5 strings and out of their stock tried some of the cheaper Fenders, squires, Yamaha BB's and RBX's and an ibanez.
I have to admit that the Fenders and Yamahas felt and sounded what I was after. The BB's were great but I found the bodies heavy and the necks very slim and they didn't fit me as well as the RBX. Unfortunately there weren't any higher spec RBX's and the one I had (RBX27?) felt so light in comparison to the £800 BB that it felt like it was made out of cardboard. It sounded good but it didn't quite have the tone of the more expensive guitar.
So after my first visit its looking like an RBX yamaha or fender of some sort. I guess I now need to sort out the difference between jazz and precisions and find a higher spec RBX to play. Thanks for the good advice.
One more thing-body wood. I imagine that mahogany gives deeper tones than maple as it is heavy but what about the other woods like ash, alder and bass wood?