StZ yeah the worlds a small place!
I just scale up or down from previous models rather than actual plans.
Your 420cc tank should be ok unless you run full noise the whole flight.
Think my tank is 380cc but on gas so not real sure on comparison with glo.
For props I run bigger diam. and lower pitch for pull rather than speed, again on gas.
Pick a few of the recommended props for your motor and experiment. ie different diams and pitch.