I think you are on the right track. Most common pitch gears on 1/10 scale platforms are 48p. You'll have some models/people using 32p gears for "heavy-duty" applications needing gears with more surface area. A lot of 1/8 scale platforms use Mod 1 gears. There are companies, like you found out, that use the "metric 48 pitch", 42p, Mod .6, or 0.6 module...all the same thing. I think Tamiya, and Redcat are among the heavy hitters using that pitch of gears.