I just find this really really strange. When any of my DC's went travelling (one does far more than the other), if I'd been offered help/telephone number/advice by anyone local in a far flung place, I would have jumped at it. Yet the OP turns down help and advice (rudely).
I was like psychomum, I was terrified about my DC going but what she hadn't covered with research in advance, I did. She was only just 18 and she was going to about 9 countries. Whilst she did the bulk of the planning, I knew exactly where she would be and when. She was very organised and meticulous, but still, there were a couple of sticky incidents that had me panicing, luckily she is sensible and level headed. However, I could have hopped on a plane within hours and got to her quickly and she had more than enough access to funds, unlike the OP's son who shas £4 a day. (BTW good luck psychomum to your daughter, she sounds very organised and it will be the trip of a lifetime
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All this seems just so haphazard, to be almost a joke. What I don't understand is.. - why can't he have a 2 week holiday to see if he actually likes this girl when he meets her? She is older, why can't she come over? Why won't she?
This boy sounds naive in the extreme. Is he worldly wise? Has he got himself to London or Newcastle or Birmingham or any big town miles away from his home?
My DCs had travelled round this country before they wanted to branch out and go abroad on their own or with friends. My DD had driven hundreds of miles round this country, she was a switched on girl. What can the OP say her son has done? You can't go from bedroom, X box and skype to halfway round the world to meet some random girl, it's just ridiculous.