As far as Bec is concerned the MMM2 should be able to handle it. The adjustable Bec voltage definitely helps and make sure you turn up the voltage. Factory default is 5.1 volts, for your 6.0 volt servos I'd set it to 6.2 volts. This way when voltage drops under load the servos will still see as close to 6.0 volts as possible. I'd also be really tempted to try cranking up the voltage even further and see if performance improves. I would think the servos could handle 6.5 volts and it might increase performance quite a bit.