“any license is valid in the a/c of it's country of registry, worldwide.”
There is an exception to this. The UK NPPL(a) is currently restricted to the UK only.
You say you want to fly to Europe, but is this for fun or would you have to make it reliably? Do you need to go solo, two up, or a family of 5? Do you weigh in at 300lb, or closer to 150?
The answers to the above have a significant impact on the cost of training and the type of aircraft you would need.
Rod1