New Redemption Grab Bag now includes an assortment of 500 cards from five (5) different expansion sets. Available at Cactus website.
Prosperity, Dull, Lawless, Humble, Exchanger, Imitate, Forsaken, Darkness, Exiles, Wanderer, Punisher, Awake, Covet (Vindicated is another LS I haven't used much myself, but have seen other people use effectively.)
A 50 card deck with three souls has the same draw potential as a 54 card deck with seven.
And if you are going to propose that this 5-LS-in-1 card start on the top of your deck by game rule... Well, at that point you might as well just propose that all LS be in a separate deck.