I've used peach puree in a wheat beer as before. Doesn't sound like too many peaches to me, just don't forget to account for the fact that some of the sugars in the peaches will turn to alcohol. Taste it before you bottle and have some peach extract on hand at that point in case the peach flavor doesn't come out as strongly as you were hoping. It's a tasty beer, all my friends start asking for it about May. Looking forward to hearing how it turns out.