The Extra 260 tends towards nose heavy because it's meant for lightweight engines.

With a Brison 5.8 twin you will need all the weight you can get in the tail, so definitely use two servos in the tail for the rudder. It may still need a few ounces of ballast back there.

For the rudder you want at least 250 oz. of torque. This means two 5645s or two 645. The 645s are good on the rudder because they tend to tolerate a slight mismatch better than a digital servo.

Use the best servo you can afford. 5945s are preferred, but the 5645 also does a very good job, even 645MG is acceptable. Alwaus use metal gear servos.

TF