Over on UrbanBaby.com, a Brooklyn parent with a 3-year-old and a baby needs a bigger apartment, and wants to know whether she should buy or, instead, rent until kindergarten rolls around so as not to end up with an unmanageable commute. Though she has private school in mind, the other parents are more worried about preserving her public school options than her commute: "Shop by local 'good' zoned schools," says one. "Finances may change and you may have to go to public." Advises another, "Buy in a good school zone now and hope you don't get re-zoned." Elsewhere on UrbanBaby.com, would-be private school parents who received a thin envelope in the mail this past weekend are dusting off their back-up plans: Renting in a good school zone. Last week we served up some options in P.S. 199, P.S. 87, P.S. 290, P.S. 6, P.S. 40 and P.S. 116. Other zones that receive the UrbanBaby nod include 183, 267, 234, 41, 452, and a new downtown elementary called Spruce.