Check a local pond club in the area. My mother belonged to one in Central IL, She got most of her koi for free after she first set it up. The the following years she would give away 40+ young koi to new members and existing members who upgraded or had a die off due to accidents.
Nice Joe, looking good. Aquatic Wildlife in Manchester usually has some decent koi stock for not too bad prices, can't remember where you are located though.