Hi Mike - Welcome. There are a few of us here from the UK and the forum actually has a group where we post specifically UK related smoking discussions.
We do have another UK based renegade from the USA who contributes regularly and who moderates the UK group. Danny is originally from Texas and so we make a lot of allowances for his strange ways . Now Colorado is a much more civilised place...
Contrary to your initial thoughts I think that you may find more BBQ related products available here than you anticipate. I too use a fair amount of pellets and they are readily sourced in bulk from UK distributors.
Sometimes the prices of US online goods can initially seem less expensive than buying in the UK however (unless you have some tax free/efficient method for buying e.g. US PX) then by the time you have paid taxes and shipping it is often just as cheap buying the items locally.
Some things are different though. The cuts of meat here vary from what you are used to in the USA and it is important to make friends with a good local butcher. Measures differ too - although cups and spoon measures are the same, the UK pint is about 25% larger than the US pint (US pint = 16 fl ozs whereas the UK pint = 20 fl ozs).
Looking forward to reading your contributions