There are a lot of options out there in the 210 mm range. For a long time I was using a 210/4.5 Tessar type made by Fuji; it's a perfectly good lens but bulky, and it's sort of been displaced as my "normal normal" by a 215/4.8 Ilex convertible that covers 8x10. (Come to think of it, drop me a PM if you want to try to work out a deal for that Fuji lens.) KEH is always overflowing with 210/5.6 plasmats, which for some reason they advertise as covering 4x5.

I actually end up shooting almost as much with a 270mm G-Claron. It's a long-normal on 5x7 and a wide-normal on 8x10, it's little, and it's ridiculously sharp. I assume the other focal lengths are the same, but someone with actual experience of them may have more nuanced information.

It's probably worth sticking with one or two lenses for a while, but to me anyway, much of the fun of LF is in the smorgasbord of interesting lenses. Brass convertibles with confusing names and funny aperture scales, process lenses abused for pictorial purposes, junk-box rescues---it's just plain *fun*. But I'm an engineer and my sense of "fun" doesn't always translate to other people's worlds. :-)