I've only been on the upright for about a year, and don't even own a full size bass - I play a hybrid BSX Allegro 5 - so I guess my comments are very much those of a newbie too.
My bass came with Spiro Weichs on it, but I wanted something lower tension and went for Innovation Silver Slaps. They have, for me, the perfect tension, they also feel great under the fingers, and I just love the sound.
The action on my bass is about 7mm at the end of the fingerboard, which is fine my playing style in both pizz and slapping.
The bass is piezo only, built into the bridge. I don't change my eq at all between slapping and pizz.
Cheers
Gareth