I'm in the process of wiring up the 1500HL with a new fuse and relay box,the sidelights are fused as one but the headdlights will be seperatly fused and relayed so unless there is total blackout there will be at least one working drivers side light.
Dolomite is the obvious route, the non HL (narrower) will fit with the same bolt holes being used, the HL seats will need a couple of extra holes drilled due to the width but its an easy job.