For an inepensive auto-loader, a used Remington 1100 or 11-87 with either 28" or 30" barrel and interchangeable chokes.
If buying new, I'd go straight to the Beretta 391 or A400 Sporter.
In a relatively inexpensive O/U, a used Browning 425, 525 or 625 Sporter, 30" or 32". Preferably with adjustable comb,
but provided there's a good fit, I can live without and have an experianced gunsmith make the neccessary L.O.P.,
pitch, cast & drop adjustments. Ditto for a Beretta 686E or one of the older 682 Sporters.
Going new, tough to beat a 682 Gold E or one of the newer Browning Sporters.