I always use 6 sided sockets but sometimes find shallow nuts where the nut head only sticks out 5mm. If you can't get a spanner in them then sockets are the only option but they can round them oft as sockets have a sloped edge at the front. I was thinking of grinding the sloped edge oft so the sockets sit flat faced onto shallow nutss. Can you buy sockets with a flat face already?
hiya
have u looked at the halfords impact professional range
gary