I think the only issue you may have is the RPM range will not be as high with a hydraulic roller lifter. If you are only running to 6000 RPM there's no reason why you can't make the switch, as far as I know. I think that going the other way, running solid roller lifters on a hydraulic roller cam, could be a problem.
I'm surprised you lost a Crower solid roller lifter; I've had very good luck with them. Do yours have the pin oiling feature?