hi chri -

i have a 150mm computar symmetrigon. it isn't a tiny field lens, but it is sharp and has pretty big coverage and in a modern shutter. it didn't cost me very much $$ when i bought it and from time to time i see them used. if you can find one, you probably won't be sorry.

the convertable lens david mentions is a good one too, and with a convertable lens, you get 2 lenses for the price of one