I'm not that familiar with the rig you are using...BUT...I can give you some advice regarding bass sounds/tones.
I view amps as simply "amplifying" the sound(s) generated by my bass. In other words I keep my bass amps eq pretty much flat, any eq settings I do are from the bass. To me it's almost like over doing it when you eq from the bass AND your amp. Plus this means I can change sounds from my bass without having to always tweek knobs on a bass head.
EQ itself is subject to each individual. A good place to start is that generally slap tones are obtained from taking a flat eq and lowering the mids giving you more lows and highs. Doing this takes the "brashness" out of the tone and creates more "punch". You can get away with this for slap and using a pic because the attack is more defined than with fingerstyle playing. On your bass this might just be a matter of using both pickups together. I usually do this and for fingerstlye I use more of the back pickup.
There are many factors regarding this so I hope I at least gave you some "food for thought".
good luck
Ray
www.rayriendeau.net http://www.myspace.com/rayriendeau
