For your 1G B6, the conversion is simple. Remove the fairing, install a headlight, and figure out a clean way to stow the extra wire.
If you want a single headlight, the clamps from a SV650 will fit your fork tubes. The headlight bucket (in round or rectangular) can come from any of the scads of different naked bikes made over the years with a single headlight - like the SV650, GS500, naked B12 and older Japanese standards like GS's CB's, XS's & KZ's.
For tires, see the tire section... be prepared to know what it is you're looking for in a tire - like do you want long-lasting or sticky? Is wet weather performance very important? That sort of thing.