rnb180 is on the right track - smaller gauge single core should do the trick, i prefer copper core with silver plated copper as the return/shield, like the VH Audio Pulsars. However, I think a big part of why their bass is so tight and tuneful is because of the eichmann bullets. I personally have noticed more of a sonic difference between connectors vs. the actual wire itself, or at least to me the differences are more apparent between different connectors vs. different wires (i.e same wire but different terminations sounds more different than same terminations but different wire).
With that in mind, you might want to try out some eichmann's if you haven't already, the silvers will go more towards what you are looking for in your bass. I don't mess around with any of those alloy like gold or palladium, silver should do the trick.
I second Jon L's rec. as well for the walker sst - that stuff works great, will tigthen up that bass probably more than any other cable you could buy since you have so many. What kind of vibration control stuff do you employ, especially for you cdp/transport? Might want to pick up some cheap vibrapods and see if that does the trick