I kinda sense that you're asking two questions here, one regarding what cool effect you could add to your signal chain, and another about taming your 'Ray.
I play a Sterling 5 strung with SS FatBeams, and that is about as growly a combo as you can get... but your setup is mighty close. EBMM makes very in-your-face basses! If you want to calm that down a little bit, my best recommendation would be to try a less aggressive set of strings. The DR nickel Sunbeams are wonderful (use them on my Lakland fretless), and walk a nice line between growly and warm, and have the same longevity that I've found with all of DR's products. Other than this solution, you could look at adding some compression to your signal path... everything you need to know about compressors can be learned here:
http://www.ovnilab.com/faq.shtml And be sure to check out Bongo's reviews of compressors for bass... the guy will NOT steer you wrong.
As for cool effects, you'll probably get a lot of responses about overdrives/distortions/fuzzes... not sure these are really going to augment your sound given the genre you're playing (I play Americana/alt-country, so I don't use these much either, although I do have a DMB Bumble bass fuzz on my board that I adore, even though it's seldom used).
I've never cared for ocatavers... they sound too inorganic for my tastes. I do like chorus when used tastefully, and there are some great bass choruses out there (I use the EBS UniChorus, and love it). I recently added an Iron Ether Nimbus bass reverb to my board. I've always HATED reverb on bass, because of its tendency to muddy up the fundamentals... but the Nimbus has this slick high-pass filter and separate dry/reverb volume controls, so you can keep your fundamental bass sound front and center. It's a really pretty effect, and I'm still learning to "play" it (it's very touch responsive, especially with fretless).
If you can, try a bunch of stuff at a music store, and see what kind of effects you like. And remember that while SOME guitar effects will work for bass, you're generally better off with pedals that were designed for our instrument.
Have fun!