Really don't see any need to purchase Ceramics for the the IGT.
I am sure some will disagree and that's fine, but if you buy a good quality bearing & not some Chinese bearing that was made with marginal tolerances, clean them on a regular basis and relube as needed, you will be more then fine.
Get a good quality bearing oil/lube and do the maintenance required. Backup bearings of all the sizes for your RC are always a MUST to carry.
As I recall 8x16x5 is the bearing that you will be replacing the most because the entire drivetrain uses them front center and back - thats 14 alone.