Sorry, Oregon is too far from Illinois for me to be hands on. I will help as I can. You can get parts from Partzilla.com, a dealership or bikebandit.com. There are others that some of those here use also. I can't remember them all though. A lot of what you will need will have to be OEM which you can get through the parts places on line. Piston wouldn't be though. The best bet for the piston kit would be to take the cylinder and old piston to a machine shop and have them measure it. Then they can get the correct piston kit for the rebuild.
Mine: 2018 Sportsman 850SP - 26" Bear Claw HTRs on OEM steel wheels(I really don't like the Aluminum ones)
Polaris Hand warmers, Mirrors.
Hers: 2019 Sportsman 450. 26" Bear Claw HTRs on Moose 427X Wheels.
2007 Sportsman 500 EFI, Polaris Winch, 25" Bear Claws QSC Clutch Kit, Hand Warmers
2001 Magnum 325 MOSE 12" rear wheel conversion. 25" Sedona Coyote tires
2017 Polaris Ranger 1000XP - Roof and front glass
2018 Kawasaki KLR650
2001 Magnum 325 Warn winch and Moose 60" plow-Sent to Daughter and Son-In-Law since his blew up
SOLD 2004 Sportsman 600 Twin