We found a coupon for Babies r Us (look online) and picked up a Chicco Capri umbrella stroller. I found this to be a good one for kids under 35 lbs. It wore well, unlike my McClaren (which holds a heavier child) Volo, which started to unstitch on the sides pretty quickly. The Chicco isn't superlight, but easy to get on/off buses, folds easily and and was manageable.
Also look at the height of the handles, because you are going to be pushing that thing a lot. I am shorter and found the Chicco handles worked well, but my taller husband (I'm a half-inch shy of five feet tall, he's a full six feet) had a harder time with this height. He did like the McClaren's height; I found it hurt my back and shoulders and was too tall for me. So before purchasing the stroller, load baby in and take a few laps around the store, see how your upper arms/shoulders/back feel.
Lastly, consider what your norm is for packing things out and about. For example, the Chicco had a smaller basket which held 'enough' for me, but the McClaren, not so much. (and all umbrella strollers will often tip over backward if you hand too much on the handles, so be aware of this. I often wore a backpack for heavier loads (small grocery trips) and put heaviest items in the bottom of the stroller, not hanging.