"The pitch of gears used is a personal choice and what really matters is the Final Drive Ratio (FDR). There are many gear pitches out there from the very old school 32 to 48, 64 and then there are the odd Tamiya metric 48 and 64 pitch gears. I even recall a hybrid pitch in between 48 and 64 that I believe was from Losi. No matter, what you need to focus on is FDR."

Not quite. Yes, 32, 48, 64 and even 84 pitch are "common" imperial pitches. Metric pitches are described as "module". Tamiya (and some other asian brands) use .4, .6, and .8 mod gears. They are not "metric 32" pitch. Amusingly, mod .6 and 48 pitch are pretty darn close, close enough to work for a while, but wear goes through the roof.

Bigger teeth are harder to damage. Bigger teeth have greater difference in shape of tooth, and have more friction. Smaller teeth have less friction, but are harder to setup right. Higher numerical pitch gears also give you a wider selection of available gear ratios. Since the OP is asking, go with 48 pitch.