Yes, the Discov3ry 2.0 will work very well with Dragon Skin. We’ve used Dragon Skin 20 a lot, and have a custom Cura profile we made for printing it at speeds of 50 mm/s.
Are your print dimensions 7x15 cm? If your build plate on your printer is big enough, this will work fine (the Ultimaker 2+ build plate print area is about 20x20 cm with the Discov3ry nozzle offset). If Artec studio can export an STL file, then this should work in any slicer software.
It is feasible to use different silicones for internal and external layers, but there will be some manual steps to do so. Basically, you would have to print your bottom layer first (as a single, separate STL file). Then when the print is done, switch the cartridges to the second silicone, level the build plate to the height of the first print, run the “purge” job to prime the nozzle with the second silicone (and purge the first silicone; you may need to change the mixer, too), then print the middle section. Finally, then the middle section is done, you repeat the cartridge switching process for the top layer.
Or, a simpler way to do the same thing would be to print the sections separately in your desired silicone, then once they are done and cured, use your choice of wet silicone to “glue” these sections together into your final object. (This approach will likely save you time and give you better results.)