Ya you still need the kit with the Sparks. With those, the track is already built into the baseplate of the bindings. Making your center of gravity lower, better control, better contact to the board, stiffer, more efficient, lighter,etc..
If you look here under the 5th picture you can see what i'm talking about
Fuse @ Spark R&D | The Splitboard Binding Company
Such a sick, sick setup for splitboarding compared to just throwing on other bindings with sloppier interplay. Others still work fine but if you can throw down the $ its pretty much the best thing going for splits nowadays....And Will is a small time dude that started from scratch and should be supported.
For the skins i should have mentioned that mine have a little modification done to accept other skins(BD's)...with the tail clips. And I have just heard and found from my own experience that glidelites are better for our conditions here; icey windblasted,powder, and variable conditions than the voile tractor skins. I can only compare those and the voiles though since they are the only i've used...
I dont know what you mean by the mountaineering people told you cant really use any others. Other than Voile tractors?? Cause you can, you could just buy the glidelites or another one without the tail attachments...I believe. I cant remember what size but they're the widest ones they make, I think.
Keep looking for a used voile kit. If you do happen to find one try to make sure it has all the little parts, everything! For example, I've found the black spacers that go between your baseplate and the baseplate track to be key on the four or so boards i've setup.
You gonna mount it yourself or have a ski tech do it?