i don't think you'd have any regrets with either of them. the JDM's have some features which are arguably better, such as auto-folding wing mirrors, and if it's the luxury version it will have brembos and 18'' wheels like a UK car. plus you'd get a newer and lower milegae import for less money. the only reason i got a UK car was because the insurance was coming through at £3000 for JDM, or £800 for UK
apparently, insurance companies work from the belief that imported cars are made to a lower quality than UK cars. there's so much room to argue that it's not worth doing but that's what they think.