They are the Militia winter head sprues: 20 heads for £4. I plan to use these heads on Cadian bodies for veterans, and for my command squad.
I also bought some Catachan commlinks to make some cheap voxcasters (£7 a piece for a Valhallan voxcaster). I got them off a quality guy on eBay that I've bough off before who mainly sells bitz: miniaturmen07. Check him out if you need a few bitz 'n' bobs.