Have you tried the Omega 8004 Nutrition Center Juicer to process chocolate? Could any of its limitations be worked around? I recently purchased one in a bid to drink more vegetable juice but also with the hope that I could use it to process cocoa beans. If not the Omega, possibly the Vita-Prep 3 blender would suffice? I would like to avoid acquiring a Champion with its overlapping capabilities to these other appliances which I own.

I've not tried the Omega, but looking at the auger, I am very doubtful it would work.  It's a very powerful press, but has no cutting ability, which cocoa needs.  As a juicer, it works great, but cocoa isn't juice or a fruit.   Also, one of it's selling points is that it runs at 80 rpm - and is cool.  Exactly what you can't have for chocolate as it needs friction to liquefy.  The Champion juicer works because the teeth on the cutter wheel chew up the cocoa, releasing cocoa butter trapped in the cells, allowing the whole mixture to flow.  And it generates a good bit of friction partly by running at 1200 rpm.

The rule of thumb I have learned to use for evaluating different juicers and grinders for this case is asking 'will it make nut butters?'.  If the answer is yes, it will work for chocolate.  If no, it won't.  I've yet to have this evaluation not work. As for the Vita-Prep 3, I know it will not work.  I tried it early on.  It burns the chocolate by running too fast. In this case it's is too much power and friction and the fact that the chocolate has nowhere to go once it starts to liquify.

This final part (a place to go) is why (in my opinion) the Champion works so well.  It cuts open the cells.  It creates just enough friction to melt the cocoa butter.  And once the butter/liqueur is flowing, it is removed from the area by coming out the screen or snout so it does not burn.