I would go with a 340 or 300. I personally recommend the 300, I will be shooting a much slower bow because I have a short draw and the IBO will only be 335 and I'm going to shoot 300's and you shoot a 360+IBO with a 29" draw.
.400 29" draw and 60# if the arrow is at 29 or shorter then .....400 for sure. .340 will be too stiff unless your staking about 160-180 grains up front. .300 will be way way to stiff.
Target archers use arrows that are between 150-300 spine and are shooting a way slower bow. Go talk to Tim Gillingham at Gold Tip he is also a prefessional target archer and bow hunter. He gave me my set up. 26.5" 300 spine GT Velocity, 100gr point, with 4 3" VaneTech Super Spine fletchings.
I have never heard anyone using that stiff of spine before for hunting. Just seems way too stiff, I'll stick to my 400 shafts
Go check out Tim's videos on YouTube or go call him. You would be surprised at the amount of information he can give you and it's all free.