The most logical choice was the plague marines, also in finecast version.
Below you'll find, once again a copy pasted description from flickr on how I painted those suckers:
Primed black, based everything with scorched brown. Then added a base layer of catachan green on the armor parts. This was followed by a wash of devlan mud and thraka green (one after another while still wet). Then started the painful highlighting process - mixing catachan green with camo green in increasing proportions of the latter. Then, another wash of thraka green, followed by light drubrushing of mixed camo green and bleached bone. Once that was done I did another wash of devlan mud and the armor was done. Getting the highlights just right and nicely blended was a true time sink :)
The heads of the non helmet wearers and most of the skulls were done by first applying a base layer of graveyard earth followed by highligting with kommando khaki. The metal parts on the armor were quite easy. First a coat of tin bits followed by a light layer of chainmail. Rust effect on backpacks and weapons was achieved by splattering spots of mixed dark flesh with a tad of scorched brown and then drybrush highlighting with chainmail. Finally a slight wash of badab black on both the backpacks and weapons.
One more pic of the squad: