Trumpeter's Modern US Soldiers Logistics Supply Team set has 2 figures in t-shirts. They are on par with Dragon's non-Gen 2 figures.
Miniman Factory also has a female truck driver figure in a t-shirt as well.
Verlinden has a Vietnam figure in t-shirt sitting cleaning a weapon that could be used as a modern figure, with a few changes.
Academy has a soldier in a t-shirt with dog tags and a shoulder holster on in their M113A2 kits. It too is on par with Dragon's figures.
That should get you started. There are probably others, but I can't think of any more.
Gino P. Quintiliani
Field Artillery --- The KING of BATTLE!!!