Dockside speaks for itself, but even Sabertooth has utility, particularly with Eternal Witness and Dualcaster Mage
Beyond these, whichever dual lands you have access to will be absolutely fine for this, whether you have Revised duals and shock lands or common duals and budget lands
It's very strong in decks that can reliably have the extra mana on the back side, such as Mono-Black Control with its Cabal Coffers
In fact, the cost per card for this product is quite low $0.63 each for 16 cards, which is lower than the on-demand proxies sold by MTGProxy
It turns a potentially awkward multi-color draw into a smooth, color-fixed hand, earning its reputation as the essential lubricant for the games most mechanical and crunchy strategies