What about a bumper pull gooseneck dolly ? It would pull better than a gooseneck, but still allows you to use the dump body at the same time.
You see a lot of slew ring, or turntable steered trailers behind Jeeps, Patrols, Pajeros and landies around here.
Because in your country, brakes on all axles are not mandatory, you can just get a simple deckles single axle trailer and weld a gooseneck hitch on it.
If you insist on brakes on the dolly, make sure the trailer itself brakes harder than the dolly or you'll jackknife it on snow.