I'm not sure what to recommend as far as a size for you. I'd guess though that for a starting place 2117 would work, that seems to be a good "all around" shaft size.
I went back myself. Started with wood, went to alluminum, switched to carbon, back to alluminum and now I have 12 unfinished cedar shafts in my stash. I still shoot alluminums right now though. I like that all I need is a small pipe cutter to cut them down, a heat source and some hot melt glue and you're making arrows. I don't like the idea of wearing a dust mask and a high speed saw to make my arrows. I suppose I could pay someone to cut them for me but I like crafting my own.
Alluminums seem to fairly available right now for little cost. It seems as though many are switching or have switched to carbon. One of the biggist drawbacks is if you miss and don't abviously bend/break the arrow. I know with carbons if it's broke, there's no question about it.
Good luck in your quest.
-Jeremy