With the Banebot motors now illegal, I would recommend the AM 9015 or the VP BAG motors as the motors of choice for an intake.
Planetary gearboxes are great for this application, either the VP Versaplanetary or the Banebots P60. I've used both with great success.
If you do have the ability to make a custom gearbox, you do have the opportunity to save a bit of weight and efficiency with a small 3:1 or 4:1 spur reduction. Planetaries are great for getting a big reduction in a small space, but intakes are generally a high speed application. A great way to do this is to use 32DP pinion gears available from AM or WCP directly on the motor and using some of the aluminum gears that are targeted towards FTC:
https://www.servocity.com/html/32_pi...l#.VmegwbgrJD8, and bolting them directly to the wheel.