A very simple hickory bow would be a self bow, that is a piece of wood carved, tillered, and sealed in some fashion. If that is what you are looking for I would advise a bow made of Osage Orange, Bois d'Arc, or Hedge, all the same wood just different local names. O O is much better suited to bow making than just about any other wood, some will argue for Yew or Lemon wood but would be wrong.
Next in line to simplicity is a Howard Hill style laminated long bow. Hill bows are primarily Bamboo and glass laminate with a simple broomstick handle. The world opens up to just about everything after that. If you have the ability take the time to shoot a few different styles. I traveled to the shop where Hill bows are made in Hamilton, Mt. I was able to watch some of the process that morning and shoot several bows they had on hand. Each and every one of them caused a sort of hand shock that made my elbow sore as the dickens. These are beautiful custom longbows, not something made of chinese mud and paper pulp. Later that day I located a nice used J,D. Chastain long bow. It is what is referred to as Reflex / Deflex in design. No shock in that bow, not a Longbow to a purist maybe, but to the untrained observer it is every bit a Longbow.
What I'm getting at here is you owe it to yourself to test drive what you buy. And yes I would say you want to be pretty near that #50 range. For general Whitetail hunting, at a limit of say 28 yards, #45 will kill just fine. Longbows are the least efficient bow so you will be shooting say 165 fps, not the 250 fps you may be used to seeing now. That arc will start getting you around 20 yards now instead of 33yds.
It's all for fun and a simple rig just seems more fun.
