single edge razors seem to be harder to come by in the UK.
Depends what sort, plenty of 1912's (Gem & Ever Ready) around and cheap - the Gem SE blade is much stiffer and is pretty damn sharp.
You get a lot of auditory feedback from them, it's a slightly different technique but one I think is easier to find by feel than by eye... I'm not sure I'd be wanting to load/unload blades without being able to see them, though I'm not sure I would with most DE's too so you're clearly already braver than me!