The only 'extra' tool we purchased for one of our tandems was a pin tool (to adjust the eccentric). And for many eccentrics you will not even need a pin tool.
Have set-up a few tandems, and as Mark implies, what works perfect on your workstand will not be as perfect when you get one, and then both riders, on the 2-seater.
But then again, tandems deliver twice the fun!
Pedal on TWOgethger!
Rudy and Kay/zonatandem