Almost anything will work. Most folks have more experience with guns then bows so try this on for size when picking a setup. A 243 will definately kill an elk if hit rite, but a 300 ultra mag will do it better. So what ever you feel comfortable with and are accurate with that's the setup you need to use. Most of this boils down to taste rather then functionality. Elk are lots bigger and thicker then deer. So get something that shoots well and is durable. 85-100g is plenty. Your arrow weight depends alot on your draw weight. I know guys who kill elk all the time with 55 lb bows and corresponding arrows. I also know guys (like me) that don't feel comfortable with that little amount of wieght and we pull 60-70lbs. Placement is crucial. Just because a guy can shoot 100 yards doesn't mean you can kill at that range.
I've used alot of diferent ones brand doesn't seem to matter, but go with atleast 100grain for elk, I use 125 grain fixed blades from wally world and they work great.
Note that muzzy's fly different than other broadheads I've used so You'll have to resight in ur bow. this is the only reason I don't use them anymore. I like to carry a few diferent broadheads on my arrows and the muzzy's would never shoot close enough groups to the other arrows.
Shuttle T-Loc 100's. I have taken 23 elk with several different heads over the years, and by far this is , in my opinion, the most solid replaceble stainless steel blade broadhead I have ever hunted elk with. They fly exactly like my field tips. They cut right thru rib bones and blades do not bend or break. Great blood trails and penetration.
From the books that I have read, there is a lot of importance in knowing every nook and cranny of your hunting territory as well as the animal that you are hunting. So scouting as much as possible, just walking the land, will give you a good idea of what's around the corner or what's on the other side of a hill. Which can be very beneficial.
Making your own maps of human and deer trails, and different types of foliage such as group of pines,...