Tony Stark's Long Sleeved T-Shirts

I'm trying to find the long sleeved shirts that RDJ wears in all the Iron Man movies and in The Avengers. I've checked these forums and elsewhere online (as well as online and local stores), but I can't find anything quite like them (even though you'd think by looking at them that you could buy something similar anywhere). Everyone seems to focus on his more flashy outfit choices, but I like the scenes where he's just tinkering in his workshop.

Here are the shirts; note that he's usually wearing a regular t-shirt over them (I think it's two shirts).

• Iron Man 1
• Iron Man 2
• The Avengers
• Iron Man 3

I'd appreciate any help in finding these. Thanks!

PS - first post here (or on any forum in years), so I hope I'm not breaking any rules.

Just for fun, thinkgeek has a "Tony Stark" tshirt with light up arc reactor. I have one and it's totally fun to wear as a lazy but still recognizable costume.

It looks like a black undershirt to me. You'd probably find it either in the underwear section, sometimes athletic wear (especially now that fall is coming), or Under Armour, but without all the logos and crap they put on the shirts. (http://www.underarmour.com/shop/ca/en/mens/apparel/tops/longsleeve)

Thanks! I'll check that out.