to marry a foreign woman or not? first off, why are you going to get married at all?
if you are looking for greener pastures overseas because you have no game and couldn't get laid in your country, then you might expect all the trouble to happen and even more. if you are simply not into local girls at where you are, then it's ok. especially if you are british or american.
rule #1 - don't mess with low class! namely don't marry a low class woman in a 3rd world country. it's a blueprint for a disaster! you might get laid with favela girls in brazil or poor isaan girls in thailand and it could be lots of fun. but, for something more serious look for someone within your social / economical strata or even higher. also, belonging to the same sub-culture is really important! you two must share a lot in common. cultural differences that you are going to cope with are enough. marrying a woman in latin america as well as certain parts of asia includes marrying extended family too. the age gap shouldn't be huge either unless you are bill gates and sean connery in one.
the age gap in asia is not much of a big deal. i know guys in their 50s and 60s heating up young asses in japan. actually one of my best friends is in his early 50s and is getting married to a 20 something japanese girl. young girls in asia, latin america and russia if not upper middle and high class are often lacking maturity and life experience. many never traveled out of their province. if you are into brainy and educated girls, russia is your best bet. there are educated latin women too, namely colombian and some brazilian with a few argentines here and there. but, nothing beats russians.
go away from tourist places, try to learn as much of a local language as you can, do something that makes you exposed to the locals (study, work) and after a certain time if you are lucky you might meet your sweetheart. such girls wouldn't be after your passport or money. be prepared to move to her country too as upper class latins, russians or asians are highly unlikely to immigrate. unlike their lower strata counterparts. most of the girls already traveled, studied and lived abroad. even if they wanna go live overseas they got ways and means to do it without you. such girls should be your target!
nothing against shagging hoes, hostesses, prepagos, shopping mall girls, waitresses, 18 year olds, ... but, there is no future! i had a great time doing my favorite coffeeshop waitress lately. a sweet 22 y/o uruguayan girl of ethiopian origin. she is even a good hearted and sweet girl. but, i can't see myself dating her. she is a bit limited and too shallow. beyond incredible sex, there is nothing she can bring in.