If you have the required hours and only have to do 2 exams + skilltest on the type for the UK CAA be aware that your UK JAR ATPL will be restricted to "UK registered aircraft only", however most countries may accept that, but ?
I did the hole lot to convert my foreign ATPL to an unrestricted UK JAR ATPL, 14 exams + skilltest on the type with the UK CAA. Pain in the .... but worth it in the end.
If you want another (additional) typerating in the UK JAR ATPL you only need to do the skilltest with an UK examiner (and have more than 500 hours on the type or go through an approved JAR course)
Cheers, and good luck