It didn't sound bare to me until you pointed it out, and now it's driving me nuts lol I added some reverb to the snare, thinking of something else that can fill that and give it a better pace without changing the mood I want it to have.
As far as synths go, I'm already using Massive for most of the instruments in the song lol I was able to pick up Massive, Razor, and FM8 for cheap last year during a sale, the whole lot for $199. Problem is, Razor won't let me do anything but use the presets and FM8 is something I'm completely inexperienced with so I spend a lot of time on Massive.
And for filler sounds, I'm actually re-downloading Synplant VST at the moment. I had it on my last rig and just haven't gotten around to getting it on this one. If you haven't played with it, Synplant is a great way to add some texture and depth to your music, which I'm hoping is just what this needs.
EDIT: Here's the current version, I think the bass sounds a bit better, I filled out the drop section a tad without trying to crowd it up too much. Left the first few beats empty, though, because I like the effect of the silence. Added some of the different-key stuff from the original song, not sure if I like it.