You'll probably get more responses if you post in the firewood forum or general. 

The 400 is a good choice, we've got the 300. You'll need a minimum 120hp, there's 2 versions - one for hand feed and one for crane. You can carefully crane feed the hand one but I wouldn't want to hand feed the crane version (awkward and dangerous). 

we chose heizohack for many reasons and don't regret it, go see one working, have a demo try it 1st, try to get to speak to someone who is using the same as you want, ask if you want more info,

Heizohack are amazing. Couldn't fault ours, K

( will look out some pics -driven by Valtra at 1080rpm on uprated clutch )

I would love to know more about this. Esp the price per ton achievable for the product....

Usually log some but send a quite a bit away for biomass as arb wood. Have thought about breaking it all up and chipping it several times. 

Remembed that we filled two silage trailers with chip in a 6 hr day, handball in cut wood in - using timber grab, on cut lengths filled it up as fast as you liked. K