Anything going into tri-color+ gets very costly with the mana base.
That said, grixis control is the way to go with a bolas deck. My personal favorite, and what I play in modern. Lots and lots of control. Planeswalkers to do your dirty work. Done.
The only creatures you should even consider are: snapcaster mage wurmcoil engine consecrated sphinx olivia voldaren
Everything else should be room for spells and land. I get away with 24 in mine cuz of how I set it up-most people want 27 in there control builds