Agree on revolvers, pumps, and even levers being a bad choice for a GP "hand-out" gun. One reason is cost, another complexity. But an even bigger reason is my ability to teach others quickly. The AR and Glock are the weapons I am most familiar with, knowledgeable about, and the ones I have the most experience teaching others to use. Also the two I maintain significant ammo, mags, & parts for. I would add a red dot to ARs, even a cheap one, as sighting is the biggest issue "new" users will have, and it provides the most ROI in its ability to improve odds of hitting the target, boosting confidence, speeding the teaching process, etc. Yes on slings, but cheap carry straps are likely enough for most, skip the two-point tactical slings.
Pistols...Glock or Glock-like in 9mm. I picked up a Taurus Millennium G2 PT111 last year for $185. 12+1, two mags, external safety, and works. I actually like it for what it is, and the trigger broke in after 50-ish rounds to be quite decent. Yeah, it's a Taurus, but at $185, I wish I'd bought three. Just grabbed a M&P Shield for $289, and it's nice, too. The Taurus wins, though, on price, capacity, ease of disassembly, and on being a better size for serious use. I keep it in the wife's mini-van, stowed away for a bad day.
Let's go a bit further...how about a simple "go" bag for the hastily-equipped clan in a disaster or defensive scenario? I think a simple, cheap backpack with 4x bottled water, an MRE, FRS radio, flashlight, 4 rifle mags, simple cleaning kit (lube, toothbrush, boresnake), couple of those cheap USCG/German made parachute flares, and a poncho.