From the pictures,I take it that it's horse chestnut and not sweet chestnut ?
What are you planning on turning ? If you want to do bowls/faceplate work,then I would cut the logs into planks,and cut bowl blanks from them.
Same if you want to do spindle work - cut the trunk into planks,then cut the planks into square-section blanks (taking note of the grain orientation)
You've got plenty there to be able to plank it all,have half of it to turn green,and the other half could be end-sealed and put away to dry for later use.
Andrew