Just to follow up, being a coward I've ordered a selection of mixed packs

Quicksilver twinthreads
Goldscrew Plus (Wasn't mentioned by anyone IIRC but they were on a clearance
deal)
Brass countersunks (for things on show like hinges and cupboard latches)
Black quicksilver roundheads (cheap deal, good for backboxes and random
jobs)

At least I won't be short for a while, and when I find what I like I'll
replenish those. Hell of a lot more than I would have got for the money in
B&Q buying as I needed

Cheers

Tim