I never did get round to posting details of what I finally decided to get for my truck.
Eventually went with Rocket Racing 18" Rocket Booster in silver. 7" in the front and 8" in the rear with 235/60 up front and 265/60 on the rear.
Now all I need to do is finish the cab repairs, fit the doors, paint the cab, fit it, fit the engine and transmission, finish and paint the bed panels, install the bed, finish, paint and fit the front end sheet steel then the interior, wiring etc etc etc.
Simples!