Higher calorie ice cream
Those ingredients you mentioned, you wanted to add, are all possible, i guess. Fat tends to make the ice cream creamier, even at low temperatures. There are many recipes out there involving egg yolk, though, because it has other properties as well. It serves as an emulsifier, which binds water to fat. This prevents separation. There are other emulsifier, too, but in my opinion egg yolk gives the best results. 

As we are not a recipe sharing site and it is definitely a matter of opinion how much of what to add (my dad adds about ten egg yolks for each liter of ice cream, but that's too much for my taste in most cases), I leave you to find yourself the best recipe on the internet. :) 

Edit: In order to stay safe, it is recommended to heat the egg yolks to at least 70°C, but do not cook it though! It shouldn't solidify! I always mix it with sugar and heavy cream first, to prevent premature clotting.