Some of the vendors are selling the mini novas in a kit form (like the full size) with all 3 attys. GV does not however.
I myself, prefer 1.8 simply because they work rather well on a standard non-vv eGo batt. However, if you have a true VV MOD, then IMO, any Ohm will do, simply crank it up. Some say the higher Ohm heads have more coils wrapped, resulting in better flavor. I wish my buds were that good to tell the difference.
Full size Nova heads do work on the mini, and you can also use stardust rebuildable heads on a mini nova as well. The problem with head swapping comes into play by using non-vision branded heads, or heads not specifically made for the vision stardust or Nova line.