Riding on the right isn't that difficult, and is a lot easier on busy roads (where you've got other vehicles to 'remind' you). If you're going to the Emmenrausch, you'll come out of the ferry port straight onto a motorway, and riding on them is easy enough. Just watch out on country roads, in town, and when turning out of petrol stations. Also, going round a roundabout the other way is 'interesting' the first time!
I found riding a bike on the right a LOT easier than driving a car. On the car I made a sticker for the RHS mirror that said 'kerb' and an arrow pointing right.
Before changing the handlebars, try a long run to see how you get on. Personally, I've had no problem with them and have ridden 500+ miles a day on numerous occasions. (Glasgow to South Coast). Perhaps it's a regional thing. Traditionally, bikes have had higher bars in the US than they had in the UK, so possibly it's a case of what you're used to. I remember when I first started riding in the mid 70s, bikes sold in the US usually had bars 3 - 4 inches higher than the same model sold in the UK.
If you feel that the Emmenrausch is a bit far for your first trip abroad, then perhaps the Dutch MZ rally might be a better introduction to European riding. See:
http://mzskorpion.mybb3.org/mzch-30th-anniversary-rally,-netherlands-t42.htmlSince you live in London, it might be worth looking out for cheap 'special deals' on the ferries and popping over to France/Belgium/Netherlands for a few days to get the 'feel' of riding abroad. (plenty of cheap hotels and campsites in France, see:
http://www.mzskorpion.net/page19.htm for details of touring in France.)
I remember the trepidation I felt when I first rode abroad (26 years ago!- I'm getting old!), but once you've done it, you'll wonder what you worried about. Riding abroad is great fun, there's so much to see, and the locals are more 'motorcycle friendly' than here in the UK. Go for it, you won't regret it!
Norman
http://www.mzskorpion.net