"Oh yes, budget is £35-45k. Any suggestions???"
I think that this budget will restrict you a bit, you will find two aircraft that fits it, the first is the Piper Dakota and the second the Piper Comanche 250, both are very different to each other. The Dakota is a fixed gear Archer, good speed and load and due to the fixed gear is cheaper to maintain. The Comanche is a very good load carrier, will fly further and faster for very little extra fuel but because of the retractable gear will cost more to maintain. Both have no problems of spare parts. I don't know anything about the TBs..