For centerpieces, you could go with a simple glass jar, fill bottom with stones or colored sand and have a candle inside. I would think that's much more budget friendly than flowers. As for decorations, go with the traditional balloons in pink and black. I wouldn't overdue the balloons though. Maybe just one of those balloon arches over the DJ or band. Flowers are one of the best ways to decorate for a wedding, so maybe there could be some. Like a centerpiece on the head table and maybe on the buffet table ~ if you're having a buffet, that is. Seeing the reception is indoors, I would mainly concentrate on the tables. Having candles incorportated will set a beautiful glow all around the room and will pretty much do the decorating for you.