hard question do you want carbon or alum? lenght should be 1.5 shorter than you draw lenght for best FOC. broadhead weight is subject too....i shoot 27.5 inch arrow with gold tip 5575 xt with 100grain heads and these fly right for my rig, i could get away with 85 gains also... again too hard of a question not enough info, are you looking for speed ,or knock down power, or full pass thru's everytime?

try this site and see if it helps: [link]http://home.att.net/~sajackson/archery.html[/link]