Try RADDS V1.5 board, the servo pins are a bit furthur away from the stepper drives ( if possible, neglect the stepper nearest to the servo pins for much better results). I use D3D quad extruders (kickstarter backer) , spent a lot of time and money for just one simple learning experience and that is "servos are meant for toys and not for manufacturing systems". Fatigue life and consistancy are major isuues even with the best servo, i mean dual BB, titanium gears, brushless servo...and so. Best of luck.
Regards
Anil Kumar
Regards
Anil Kumar