If I learned one thing when I was trying to make straight flushes work it's that you're going to want actions that you can use during noon. If it's all shootout and resolution abilities they're going to start clogging your hand which makes getting a straight flush a lot harder. Especially once you start buying shotguns people will be wary to start fights with you so you're going to be waiting on your Kidnappings.
That being said, shotgun decks don't always need the shootout power until later in the game. At which point you should have big studs to help you pull big hands.
Personally I'd lose two/three Winchesters for some combination of dudes/deeds. Shotguns are expensive and so is Remy's ability so being able to guarantee a deed T1 is very important. Also if you plan to make use of Hot Lead Flyin' you'll want to be able to replace whoever you lose.
Fair warning, all my shotgun/straight flush experience is out of Law Dogs so my advice could be completely off base! Give it a few test games to see what you think you're missing.
