Yellow perch and 2 brown bullheads. Green sunfish would destroy those shiners. Have at least one huge peice of driftwood for the center peice in the tank.
Your going to need a much bigger tank for a walleye. With a tank that size you could have a bullhead, 3-4 perch, 1-2 green sunfish and 2-3 grass pickerel. I just fed my pickerel a dozen rosies. That fish is a killer.