If you want the highlighted, do limited. Premium is an "all-included, all-treated-equal" draw. Which limited ones are the best? The ones you don't have (look at the gold highlighted, honestly, the rainbow draw chance is .5% (1/200) regardless). Often, the Type-Up (Pierce/Slash/ Magic/Hit) is best if you need that type just because the ENTIRE CAST of that type is boosted chance instead of just 3 units, at least one of which you have a 1/200 chance of drawing just that rarity, let alone the boosted unit in particular.