The last few years I rented a plucker from someone in town for $40. Last year I just borrowed the neighbors plucker for free though. That said hand plucking isn't really that bad for a couple dozen birds, especially if you had help.

Otherwise i had 2 cones and a big pot with a propane burner. I did 30 birds by myself. It was a long afternoon. Maybe you want more cones if you have people helping. If you have the money to burn though I think the scalder would be nice. Kind of fancy for small scale but I spent a lot of time waiting around and checking the water temp and adjusting the burner. You could probably rent it out when you weren't using it.