I used to play at a church that had a little Japanese Fender active PJ. That bass had about the best slap tone I've heard from a bass under $1000. It was active but I usually just ran the EQ as flat as possible and had both pups on 100%. It was punchy, growly, and had a nice high-end pop to it. I used to bring my Lakland 5'er to play but after a while I just left it home.
There's really only one way to get a good opinion. You have to get a hold of one yourself and play one. Everyone's idea of a good slap tone varies so what may work for me may not work for you. I'd almost guarantee that your bass will have a good tone to it once it's modded. If it doesn't you still have a P bass.
I have a 55-02 that I can't seem to get a good slap tone out of. I'm only beginning to slap, though, so I'm not sure where I should be setting the knobs. I know to take the mids out, but I'm not sure by how much. Can you give me a hand? We can take it to PM to not hijack the thread...