dtrevatt,
If you've got the cash, I'd give
Oxford Aviation Training a call. They do a 3 day battery of tests. All the details are on their site. It all costs £140ish, but from the looks of it, it's a good indicator of your overall skills and potential. I contacted them and they got back to me straight away. Seemed like a decent bunch

, and they've got the reputation everyone wants.
Good luck