I have found there is a lot of variation between the 3. It depends which part of the antler you are using too. The biggest difference is how thick the outside is vs how pithy and hollow the inner core is. Its best to look it over in person if you can so you get what you want.
Go to www.moscowhideandfur.com. They got the best assortment of antlers. Send em an email, tell em what your doing and how much material you want and they'll pick out the right piece for you. Got an elk beam with rosette a few years ago and finally used it all up.
You can usually get deer antlers cheap at a flea market or someone may have some in their garage they'll give ya.
The real best, overlooking natural variations from critter to critter, is Indian Sambar Elk, but it is getting expensive, and harder to find with good quality.