Interested in wood pellets, 600t a month

Wood pellet is of interest. Our need is 600 tons / season.
We want to buy about 200 tons during the summer, and the rest - during October-February.
In this case, we need a contract with fixing price. Form of cooperation: ready to prepay 50% of the total amount immediately after signing the specification, and the remaining 50% - as pellets are delivered to our warehouse.
Notify the price for supplies in big-bags, the price of delivery specify separately (Uman, Cherkassy region).