My cyma glocks gearbox is in the grip though, or do you mean it's the same style??
As for the motor 370 is the size, have a look on eBay at item number 251321130110
Recieved my scorpions drum mag today . . . It's soo cute lol
Hop doesn't kick in immediately with a titled gun (at least when I've experimented) and if you're using canted irons/an RDS you'll only be aiming with that backup because somebody's too close for your other optic.
There'll probably be a bit of 'dead ground' in between the maximum straight flight distance of your BBs with the gun canted and the minimum useful range of the primary optic, but that's not too big of an issue IMHO.