The gen 2 IMS looks very intriguing. If I were to source my own ceramic 6204, I'd choose this one
[BO] S6204 Bearing 20x47x14 Si3N4 Ceramic Open Premium ABEC-5 Bearings:HybridCeramicBearings just beacause I don't like the thought of a nylon cage. I bought the Pelican parts retrofit for the stronger bolt, but replaced the NSK bearing with a Nachi because I liked the Nachi seals better and am trying to keep the grease in the bearing. I also modified my IMS shaft to keep the grease in the bearing. If I find the grease leaves the bearing after about 15k miles, I'm dropping in an open ceramic.