I've got a gas lamp but on my last experiment it threw all the background into darkness, so to keep the setting sun light and colours will need further experimentation.
I've got a gas lamp
It does the job, but I'm not impressed with the size, price or control interface. If I was you I might go for a 2nd hand last generation flash and a cable.
not to mention the post-D70 i-ttl cameras can only use the old flashes in manual mode or some shit like that anyway.
it would be easier to wedge my johnson against the viewfinder.