Actually DUST troopers are about 32 mm. from the ground to their eyes so the correct scale should be 1/56, 1/48 being a bit bigger (about 37 mm.?).
Vehicles still look OK being a bit larger than minis and some equipment could work (bags or mag pouchs) but weapons would look large. Not a very bad thing looking at DUST infantry basic weapons but definitely not desirable when looking at "real" weapons to convert the minis.
So It would look like ideally 1/48 for vehicles at most (mandatory for planes as they will look too small besides armoured infantry) but 1/56 for infantry equipment-conversions. A useful link:
Exploring will bring more pages in the site with useful links.
It has to besaid that it may be weird but 1/48 seems more appropiated for DUST. I'll have to check and then post again...