Most 64pitch spur gears with a 4-hole pattern should work with the high speed mount. Some gears only have a 6-hole pattern, which may still work only with 2 screws instead of 4. 2 screws should be ok for a low power motor like a 17.5t. Pinion gears must suit a 1/8" or 3.175mm shaft, which just about all 64pitch pinions will be. Arrowmax and RW Racing make good quality gears.

With an 82t 64pitch spur, pinions larger than 44t or 45t will not fit under the unmodified gear cover in my experience. I would get a 82t and 44t to start with, which should get you going somewhere around 24mph on a 17.5t motor and 2S battery.

I have run down to a 69t spur and 60t pinion in my TT02 which required a lot of the gear cover to be cut away. This would get you around 35mph on a 17.5t motor. Motor might get too hot with these gears unless you run only on smooth concrete/asphalt, keep the speeds up and/or have a decent motor cooling fan.

Additionally, consider using a 3S battery which your motor/ESC should support but watch those temperatures! Speeds should increase approximately 50% when you swap a 2S battery for 3S. Heat from the ESC/motor will increase 100%.