You could also check out the SWAT teams from Foundry ,the horde deal isn't too bad when they do a 20% off sale(that's how I got mine).
I'm using the Copplestone guys for Spainish Paratroopers and the SWAT teams for Spainish armored infantry in Weird War.I ordered some Empress SCW for the normal/regular types.Doing pretty much the same as you.Using my regular historical figures for well...regular troops and near future for elite type units with new weaponry.
Got the Westwind SOTR stuff for the other countries.
Another thing is try finding some 50s early 60s troops.There is a company doing Malaya I believe and some early Vietnam could work too.
Pete