The best RC grease is TrakPower waterproof grease. It doesn't break down and has anti-sling properties. Comes in a little tub. Under $10. Will last you for years.

For general lubrication, TrakPower Dry Lube. It's a wax lube in a liquid medium that leaves a lubricating film that doesn't attract dirt. Good for CV joints and drive cups.

You can use the dry lube on the bearings, but I would use a little of the grease. Pop the bearing seals out with a hobby knife, clean the bearing, and with the knife, push some grease into the bearing, and replace the seals.