Thanks! That's excellent advice, and not something I had thought of at all, but now that you mention it I do see comments elsewhere on the forum about the need to keep 5-speed SA hubs in adjustment, and problems that arise with them. My plan was to order a 3-speed, and then convert to 5 speeds, but maybe I'll revise that plan slightly to ordering a 3-speed, trying it for a while, and then deciding if I need the extra gears. Vancouver has some hills, but it's nothing like San Francisco or Seattle (I've never been to Glasgow, so I have no idea how it compares), so super-low gears aren't essential.

Cheers!