Not sure what your price point is but a Bushnell Trs-25 is a great little red dot for the money. I have one on a 590 and I shoot slugs primarily at ranges and classes. Best of luck!!
Just go with what's proven. First name that comes to mind and a rifle most people have would be an Colt AR. They're in the $850+ range and a great rifle out of the box. Most stores have them, parts are inter-changeable with other brands, they're reliable and easy to maintain. If/when the SHTF...
Picked up a AAC 16" 300 BO upper from Duffys a while back. Threw it on a Stag lower with no problems. Ammo is a bit pricey unless you reload. Best of luck!!
http://www.advanced-armament.com/300-BLK-Upper-16-Barrel_p_463.html
I like that 1-6 you got. I have a few 1-4s. The AP mounts are great. 1inch and 30mm available. I have a few of these.
http://www.ebay.com/itm/Aero-Precision-Ultralight-30mm-Extended-Scope-Mount-AP210500-/151603056641?pt=LH_DefaultDomain_0&hash=item234c3f1001
Windham HBC is MD compliant. Don't let the heavy barrel term scare you. Its about 6-7 ounces heavier than a typical AR. Picked one up from Duffys about a year ago. Great gun. Similar to RRA and STAG in quality. All for around $850. Not sure what the previous poster meant about mag issues, but...
Aero Precision mounts and Vortex 1-4x24 scope. Mounts are extremely light and priced sub $100 and a 1-4x24 will take you from a hallway out to a few hundred yards. Vortex Crossfire $180-$250 depending if you want the center dot lit. All the best.
Setwear Stealth gloves.
http://www.ebay.com/itm/Setwear-Stealth-Gloves-Black-Medium-/360830828985?pt=LH_DefaultDomain_0&hash=item54033181b9
Nice tight fit, various sizes, no problems with standard size trigger guards, etc.
Had Mechanic and Oakley with the fiber knuckles. Like these way more.
Duffy's is top of the line. Only shop I purchase from anymore. Vince is a great guy and their gunsmith is pretty cool too. Came in the other day to have sights put on a glock thought I'd have to leave it a day, did it right there 5-10 min. Great inventory and ammo selection. I never walk out w/o...
You ought to try the gun shack in mt.airy. They are only another 10-15 minutes out 70. Good selection and close. I'm in the Mossberg camp too, specifically 590. If you can't find one than a maverick 88 is in the $200-250 ballpark. Best of luck!