unfortunately sat night, not much is going on in philly, call espresso cafe in northeast as they might be open(30min drive)
Sun brunch, again usually not much going on, go to Roz to p/u some bake goods or have lunch at Mamas(the best falafel in NE)

fairway carries cappiello's

They are open from anytime in the morning, although official help usually arrives around 8am but before that the owners/bakers are in the back going back and forth to serve early customers. They are open till 4pm9 i think M-W, 6pm Th, and 30min-1hr before sundown on Friday. On Sundays they are open till 4pm.
They are located in a four story house offically on Montgomery Ave, but the bakery is on the bottom floor facing the outbound train station.
Like everyone says, challah and bagels are great, as well as their other breads, other things depend on your tastes. Humantaschen, small cookies i think are really good. They pride themselves on using quality bakery products including real fruit.

Mazel Tov, I hope everything goes smoothly and you have many occasions to celebrate.
Since wedding cakes are hard to transport, maybe you should try something in Monsey if possible or maybe in Teaneck. Butterflake bakery in teaneck should be able to make a great wedding cake. Its under the RCBC.
Zadies in fairlawn should as well, they are under the RCBC and the Star-K(?) as well.
Good luck and mazel tov
Rob