A good box rim, Mavic OP, Ambrosio Excellights, 3x laced will do you quite well unless your roads are hellish. If your roads are terrible you might want to look at heavier Aero profile rims, these will withstand vertical misshaping due to potholes better. You telling me Portland has more than one bike messenger zone? You said your were working the East, and not the core?

Damned straight on the Paké, you'd have to run it right into a brick wall to wreck it.... if you kill that while messin' ... then what to ride is the least of your concerns because chances are you're in the hospital. I bought mine used, put used wheels on it , only just getting the Ambrosios built recently. I've a mismatched crank, 1/2 Sugino 1/2 Peugeot that came off a bike I found, I'll be putting on my Steelwool 1/8th crank on it soon. I messed for a good couple years before getting any respectable gear, and even then it was all used mostly. Granted I was messin' when you were in grade school most likely, though not a hell of a lot has changed, cept I made more money back then. The BIG fashion items in the messenger crowd back then were Oakley sunglasses, and clipless was just making it's inroads to market domination.

IMPORTANT: Get the wheelset hand built for you from someone respectable. They should ask how much your weigh, tell them it's for messing so to add 20or so lbs +/- to account for a loaded bag.