I am also a 34B (lower mileage) runner, and I recently bought two Champion Double Dry Seamless Full Support Underwire Sports Bra in size 32/34B/C (size 1).

They fit really well (on the middle hook of three, for me) and support like crazy. When I first tried them on, I thought "wow, that's a lot of bra", but during my runs I never even notice I have them on. They also wick sweat very well. You can often find them on sale online. I got 'em here on sale and with free shipping if you buy two.

Good luck!
Emily