I'm not much into "long guns" at this time but for a new or entry level shotgun owner I'd suggest a NIB(new in box) Remington 870 or the slick 887 Tactical.
Other models include Browning's BPS & the Mossberg 590/500.
I'd look into a Knoxx spec ops stock, www.Blackhawk.com
& maybe some custom work from Vang-Comp or WilsonCombat.com.
A custom plate job like Bearcoat.com or Robar's NP3+ will ease clean up & protect the weapon.
It's not cheap but it add value to the shotgun and assist you greatly.
www.Browning.com www.gunsamerica.com www.jgsales.com