I've tried various techniques, like scooping out space for the kick drum out of the bass range in the EQ, but I end up with a weak kick drum! 

I tried side-chaining the bass to the kick, so when the kick hits, the bass ducks. This worked to prevent the bass and kick from compressing against each other, at least. But there are certain times where I would like to fully hear the kick and sub played together, and this defeats that purpose.

I really would like both sounds to have equal importance in the output, but not be so low that you can't hear them over everything else in the mix. Is there a such thing as 50/50?

How can I get the Dubstep-esque rattling sub bass to play well with a 808 kick drum (or any kick for that matter)?