Might I suggest an Original board of some kind? They are literally the shit. You can't downhill on it but seeing as you already have a downhill board, an Original would be a pretty legit addition to your quiver. My favorite thing for cruising around town. They aren't as good/comfortable as a drop thru for long distance pushing or anything because they are on fat risers, but they are kick ass for pedestrian slalom if you live in a pretty crowded city.
If you haven't heard about Original look it up on Silverfish or something, but my god man, it will change the way you think about a carving board. The whole way you skate on that thing is different. You can throw your weight so far into the turns, its like surfing or something. Fuckin miracles man.