www.bohning.com
Will have all the things necessary for your dipping and cresting if you like. There is very little difference between the weight of dipped and crested arrows and arrows that have been wrapped. Also like someone else mentioned...it won't affect your arrow at the ranges we usually shoot a bow and arrow.
I dip and crest my own. Not that I think they're any better, it just gives me something to do this time of year instead of watching it snow.