In the end, all the companies dont give a crap about which country is the issuing one.. as long as you have a JAA one when applying for a job in JAR-land.
Considering the amount of useless rubbish they teach, stick with a country which language you truly understand and am fluent in. Reason is that alot of these obscure written questions are written to catch you out.. obscure grammar and confusing options. So do whats easiest and hence cheapest in the long run.
Yes.. this JAA lark is very much like George Orwells "Animal Farm"... we are all equal but some are more equal than others.