I did the Engy at last years Fan Expo, and most of the stuff for him wasn't too hard to find. Thrift stores are your best friends. It's where I found my red button up shirt. For the overalls, thrift stores, outdoor/camping stores, army/navy stores, Wal-Mart, or even places like Home Depot or Lowes have carry them. I know Lowes and Home Depot have hardhats and toolkits as well. I'm not sure what MetroCon's weapon policy is. I know for FanEx I was allowed to bring in an actual wrench. The shotgun and pistol can probably be bought at various toy stores. The Wrangler can probably be made out of an old school joystick controller, a pistol grip (if you can get an extra toy shotgun that has the pistol grip, you can break that off rather easily, as I learned the hard way) and whatever you want to use for the other, part that my brain is failing me on. For the knee pads and tool belt, Lowes and Home Depot have them, though you'll have to probably paint the knee pads. Boots can be found anywhere. And don't forget about the extension cord. Many tool belts have hooks on them, so you can hang the cord on there. Dispensers, Sentries, and Toasters are optional, but if you bring them, you'll get tons of praise. I hope this helps you.

>>916
Yeah, you can't bring a real wrench to Metrocon - one of the Engies last year had one and couldn't keep it.

>>918
I was thinking that, but wasn't entirely sure. You might be able to find a toy wrench at a store. I know people have made them too. But I'm not exactly the best person to ask about making items. Busted PC is an excellent prop maker, though. I can always ask him what would work best.

Also, I derped and forgot to mention the goggles. Home Depot, Lowes, hardware stores like that should have welding goggles.

Oddly enough I'm having the hardest time finding a reasonably priced pair of overalls. Everywhere I look online they seem to cost anywhere upwards of $40.

>>920
Most of the stores you mention have started carrying welding goggles of the single-rectangular-lens variety. Last year I had a hell of a time finding my Engie goggles. Ended up finding a pair for less than $10 shipped through Amazon. (Like this: http://www.amazon.com/Welding-Cup-Goggles-5-Shade/dp/B002DLYR8A/ ) Search for "brazing goggles" if that pair doesn't suit. You don't want the flip-up front kind - those are more Dr Horrible, and are far too big for Engineer.