I would certainly go after an older gun. Remington 870, Winchester M12, and the Browing BPS. The Ithica 37 is nice too. I am not sure about the others, but I think you can get a slug bbl for an 870. Your hunting choices suggest different choke needs, and as much as I hate them, you may need choke tubes.

I have not hunted upland in years, so I do not know if there is a steel shot requirement, beyond just migratory birds, but putting steel through a gun not designed for it will stretch your choke for you

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Pete
I ain't no fortunate son