It has been my experience that 25.4 grain pellets shoot exceptionally well. I use the FX branded pellets because they were available when I bought some, but the JSB redesigns (which are virtually identical to their FX counterparts) work also.
Personally, I’m far more interested in shooting pellets anyway, so it worked out great.
Now granted, I usually shoot between 30 yards and 50 meters, and have not yet tried 100 yards, but I’ve been happy with pellets so far.
Stay with the heavier pellets and you’ll do just fine.