Also, for any shotgun with a forend cap, you can use this device sold by Weatherby to add a flashlight mount onto the shotgun:
http://www.weatherby.com/product/acc...ccessory/44408
I got one for my Weatherby SA-20 and I have a Daniel Defense flashlight mount on there with a SureFire 320 lumen flashlight on there. You can actually use this same device on the end cap of the mag tube of a Mossberg 500 persuader 20 ga, too, and I think you can use it with just about any shotgun with a forend magazine tube cap. And, you CAN still have a forward slig swivel attachment point if you want (comes with the railed device from Weatherby.)
And, if you do go with a Mossberg, these guys (ATI) sell an aftermarket pistol grip with adjustable shoulder stock (M4/AR-15 style):
http://www.atigunstocks.com/tactical...il-system.html