It seems to me that one can find ABEC 3 R6 LLB, or ABEC 5 SRS. Both LLB and SRS seals are find for bike purposes, so the SRS (providing they're actually the ABEC 5) are an upgrade.

I'm a bit confused, though, about how you found out that they're filled with "crappy white grease". Aren't they sealed on both sides? The LLB seals have a steel ring inside them, and the SRS have a metal ring on the outside. How did you assess what grease was in the bearing? Did you remove a seal? Or are these only shielded on one side?

In any case, if it is the specified grease (Nye Rheolube 374b), it's actually an exceptionally good grease used in machine tools and elsewhere in high temp, high speed applications.