I'd say best balance between fun, cost and utility in the UK is a 90HP Super Cub or converted 90HP J3 with a wing tank. the 150HP is more expensive to run / keep and the J3 / L4 with a 65HP engine lacks guts two-up and range too.
I like the 150 and its flaps, but am not sure of the cost/benefit in the UK.
QDM