I shoot Beman ICS Hunters. I have a 29", 62# draw on my Mathews. My arrows are 29" 400s. Go to www.beman.com. There is a shaft selection guide. I took a quick look at 70# and you would get 340s or 360s. The beman site also shows you how to measure the appropriate arrow length.

I just bought a dozen of these from my local bowshop and they ran me about $100. But I was recently on eBay and saw them as low as $60 per dozen. Good Luck.