I have available some sets from walking onions.
Walking onions, Egyptian onions, topsetting onions, etc. are weird things:
http://www.google.co.uk/#hl=en&sugexp=g ... 4&bih=1231
Very strong and, after a few years, spread well in many soils and like dry conditions. You won't get much the first year or two but then they take off giving small onions forever with no cultivation.
Anyway, if anybody would like a few sets I can easily post them out, just send a PM with details.