I had a commuting "incident" and busted my leg in a complicated way (wearing nice comfy, waterproof boots) - going about 30km/h... Now I have a pair of MX boots: Alpinestar Tech 8's - a great boot. I liked the SG10s too but they didnt fit me as well as these (neither did the Tech 10s). After a week or so MX boots will soften up a bit and become easier to walk in, still not hiking boots, but much more protection than the trials boots that seem so popular. Waterproofing can be improved with some snowseal.
Have a bloody good trip.