Dre - we get most of our stuff from Gamaliel......now our club buys it at a wholesale level because they have a resale license, but the mark-up is minimal.
Graf's is another one I have used as well
PowderValley is another
The Lyman manual is always a good recommendation. Every powder maker will have data available for free (they want you to use their powder)
FOLLOW THE RECIPES and do NOT ASSUME you can substitute primers, wads or hulls at will (that's MY disclaimer)