I would go for 4 Sycamore, 4 N, 1 Colress and 1 other in a deck with no Shaymin. I don't use 2 Colress because it is a bad card to start with. Especially with 4 VS seeker, you can usually get it if you need it later. For the other, I used to play Shauna just because it is usually okay at any time in the game. But if you have Shaymin EX and Hoopa EX, Pokemon Fan Club can be very good. If you are playing some sort of Bronzong deck, for example, the Fan Club could get you a Bronzor and a Hoopa, which could then become a Shaymin, and two attacking EXs.
For most decks I'd hardly ever play this engine, though, because most decks do have Shaymin. I find you can go down to 8 draw supporters with 2 Shaymin, 6-7 with 3 Shaymin and 4-5 with 4 Shaymin. This assumes that you are running a full count of ultraballs and maybe some extra consistency cards.
The tricky question for me is how to cut the supporter line. I know the majority cut Sycamore last- so if you want 6 draw suppporters it will be 4 Sycamore and 2 N. Personally, I don't like this that much. You are moving from a situation where 40% of your draw support was Sycamore to a situation where 60, 70 or 80% is Sycamore. It means that when you are trying to maintain your draw, the chance of it being Sycamore is much higher, and the chances of having to dump good stuff is higher. Sycamore is the most powerful draw support, for sure, but I am not convinced you need it quite so often when you have Shaymin, Hoopa and the item-based consistency cards we have now. So I look for a more balanced split, e.g. if it was going to be 6 draw supporters I would play 3 Sycamore, 3 N (rather than 4/2 in favour of Sycamore). I know this is a minority opinion, but there it is.