I suggest rogueriverarchery.com in Oregon. Paula and Cecil are great to deal with and will be glad to help you with any questions. They have raw shafts if you want to try and make your own, or they sell completed arrows, both in tapered and parallel. Whatever choice you make, just make sure they are a reputable dealer. Best way to do that is go with suggestions from folks that have shot arrows from them.
My crusader shoots 55-60 spine arrows cut to 29 or 30 in. just fine. It is 51@28.
As far as attachment of heads, I use hot melt glue sticks, the ones you buy for the heated guns. I get a pack of six at Home Depot, Walmart, of any hardware store for about the price of one stick of glue that they say is for heads only at an archery store. I have never lost a head yet. Just be sure you clean out the residue and oil in the head from the manufacturing process with alcohol. I also take a 38 caliber brass bore brush and scuff it up abit.
Arrows for broadheads and practice heads is your choice. I usually glue broadheads on 1/2 doz arrows that I feel shoot the best of them all right before the season. That way I have freshly glued heads every year with the straighest shooting arrows that I have at the time.
I'm sure several other guys will jump in here with help and suggestions. This will get you started. Hope this helps, good luck, you won't be sorry you switched to wood. There is just something about wood off a longbow that makes it right. John