VA,
I forgot to mention.....if you go over to this site you can " build" many popular brand names of arrows by plugging in different shafts and components. You' ll find many popular brands there and you' ll be able to see " virtual" finished arrow weights which will help give you an idea of what you might want to buy.

www.bowjackson.com

If you check there and the manufacturers spine charts you should have no trouble getting in the ballpark for a correct arrow selection.