If it's a self-contained Whew! you want, try a round-robin format. Three players, each blocking against one opponent and charging against another. Here's a hypothetical example:
Round 1: George blocks, Matt charges
Round 2: Let's say Matt won round 1. George now charges, Chuck blocks.
Round 3: Chuck charges, Matt blocks.
If one player wins both their rounds, he goes on the Gauntlet. If all three players win exactly one game, the player who accumulated the most money wins.
Random thought: we've seen video of three Whew! openings, one closing, and two Gauntlet runs, both wins--but never an upfront round. I wonder if someone is eventually going to upload one, because all I know about how it's done I learned from Mike Klauss's ICQ transcript from six years ago.