RE: best heavy longbow?
I don't know of anyone that will go up to 100# on a longbow. Due to crap like insurance rates and frivolous lawsuits, lots of bowyers and companies are limiting how high they will go in poundage--that, and the fact that 100# isn't required for any animal on the planet.
Why are you wanting to shoot 100#? Just curious. You may live to regret it later on in life.
Chad