Rocketman, although most two gauge sets are built on the larger of the two frame sizes, they wouldn't necessarily have to be. Example: The Merkel 1620 has 16ga barrels on a 20ga frame (which is why it's light). There is a two gauge set, 20 and 16, again on a 20ga frame.

I'd go with the Repro, preferably with 28" barrels . . . while wishing very hard that both the Repro and the RBL were offered with the combination of long barrels and chokes more open than M/F.