I'm, afraid I use the normal archival sleeves with commercially deved, 4 to a strip negs and have to use two sheets of 8 x 10 paper per film for the contact prints. It might be less economic, but it works. There are labs here that do send back strips of 6, e.g. Lab 35, so you probably get them over there too. Actually, though, I quite like having a bit of spare room on the contact sheet. I always put a cigarette pack on the contact printer to hold back a white area to write the film number and other information on.

I used to have a dust problem in my dark room. I got two little electric domestic air filters and have them running 24/7. It's like an industrial clean room in there now and cost next to nothing (from memory less than 10 UK pounds ($18) each.