I use mainly Klingspor gold disks as they cut well and last long.  I also use their 1" rolls both the gold and regular.  Klingspor has reasonable shipping costs and ships quickly.

Awhile back, I bought the Klingspor box of abrasives.  The sandpaper was about 10" wide and grit from 40 to 220.  I mount pieces on 1/4" MDF that are 12 x 18" and use it for flattening things.