Well, I can't speak for the Shadow Sport, but with my Whisper, the best pellet for overall use is Crosman Premier Lite Domes (7.9)
I've tried everything Gamo has to offer and even though I get higher chrony numbers with the Gamo stuff, the Premiers are far more consistent, even in windy conditions...
Short range, long range, hard impact, penetration, it does it all very well and still remains consistent
The Premier Hollow Points are my second choice and what I usually use for close range....
Rick