id go ssl5 (or ssl6 for flat pole) neck and middle over the ssl3, more juice than the ssl2 but not quite as much as the ssl3. if you use all ssl3 pups you end up with a thicker higher output verison of a vintage set where the pups are all the same which can lead to the neck over powering the bridge. by using the ssl5/6 in the neck and middle you get more output and a fatter sound but wont be as likely to over power the ssl3 in the bridge. do you use 500k pots or 250k?