in addition the the advice tony gave you ...

you might think about a schneider symmar convertible lenses
they are worth their weight in GOLD .. BUT their nodal points are not the same
as a "normal" lens. when converted they take more bellows than you might think ..
plasmat lens design beautiful color and b/w rendition too.
don't overlook them 2 lenses in 1 !

i am a fan of older lenses, less sharp ( well not really ) but old glass seems
to be less "clinical" than new. i also have tony's love of old tessars
mine's also a pre war uncoated one, a 21cm f3.8 fast and beautiful

good luck !
john