List of Premium Combos?

I'm not entirely educated on different types of combo card... but the Gold cards have a list, can I assume the premium cards also have a definite sequences?

Nope, they are randomized, but you can change which skills are in the card by using a Combo Card Slot Change Coupon.

so these cards are better than golden cards only because people can pay to randomize each slot's skill? :|

If you consider that better, then yes.

For what it's worth, I spent a good deal of money trying to see how hard it is to get a card tailored specifically to my skill set. It seemed like that the chances of receiving a skill from the same skill tab gets less likely as more of them appear on the card so it gets really expensive really fast. It might even be worse than reforging from scratch with less benefits.