Hi there.
My recently completed UK rating has just been added to my Irish licence, no questions asked. Of course a JAA examiner can sign your Irish JAA licence, on my licence it says: "Issues and renewals of expired ratings may only be entered by IAA". Revalidations however, can be entered by any JAA examiner. A friend of mine flew for a BA franchise and they signed his checks in the UK.
The IAA will accept ratings from many other countries (remember though, JAR are not law, so consult the IAA beforehand).
My groundschool and test were in English and about 25% cheaper in the Czech Republic, so maybe that would be worth giving a thought? Or sunny Croatia (Lufthansa / intercockpit.de) or Slovenia, etc. etc. for that matter? (Is Malta JAR yet?)
regards, IP