I'm looking for advice on a set of panniers or a rack-pack to get for general commuting/running errands; something detachable with handles/straps that I can carry around would be the best, and preferribly something with a lot of cargo space for store-runs.

I'm also going to need to get a rack; the Crossroads I have has the eyelets for a rack, but I'm not too sure what would be a good bet...ideas?