well, i'll have to say that i was just in your town for a week and i absolutely loved it. xcutterx and i built up a fixie for a friend living there and we set it up with 170 cranks, 47t chainring, and a 15t cog. he seems to get along great with this ratio, but there were a few hills that it was a little tough. mostly when we rode up to the rose gardens and zoo. there was one hill that was just nearly impassible. the primary riding we did was from 35th and hawethorne and into downtown. excluding the zoo, this ratio was perfect for him. i run 170 cranks, 48t chainring, and 16t cog on both of my fixies. my ratio is just a bit easier than his.
going down those zoo hills made me think i was glad i didn't bring my brakeless fixie. i'm sure there are ways to circumnavigate such hills. he also is new to fixies and is glad to have a brake. it's better to have one than to want one i guess.
i ride clipless, which has a learning curve of its own. he has cages on his bike. i think it just depends what you prefer. clipless is waaay more responsive than cages. one way or the other riders in general seem to think one is a death trap. if you go clipless i would really recommend mtb pedals and shoes. that way you can actually walk around with some grip. i couldn't imagine having to walk anywhere in road shoes.
cliff's notes:
1. get a fixed/fixed hub and get two cogs. i would recommend 48:16....
2. go with what makes you feel comfortable on the bike.
3. go with what makes you feel safe on the bike.