>>3133758I recommend the free-est one you can find.
You will print 4 photos and never touch it again.
Seriously do not worry about the lense either. They will all produce very acceptable prints from f/8 onwards, presuming they aren't destroyed by filth or fungus.
If you have the option or the insatiable urge to spend money, however, 6-element f/2.8 lenses are the way to go.
For heads, colour diffusion models are the easiest to use. Condenser models are sharper and brighter, but require scrupulous dusting of all condenser elements, and the filters and the negs to produce perfect dust free prints. If you're not autistic about dust, or alternatively you are massively autistic about it and print in a climate controlled, HEPA filtered clean room (yes really people build these for printing) they they are the way to go.
Older Durst and Leica models seem to need a whole heap of expensive and hard to find parts to change lenses or masks or filters, etc, so I'd avoid them.