Again I've used MaxminiEU Biohazard heads and backpacks. I'm really into these, they give an interesting look to the miniature. Heavy duty breathing apparatus that seems to be powered by a personal furnace.
If you like this stuff, then you can find it here: MaxminiEU
I've also used Anvil Industries Steam Lord medieval legs, which I think give a nice pre-Heresy feel to the models. You can find their stuff on eBay, or on their website: Anvil Industry
Anyways, here are some pics.
| Before I glue this together, I will drill out the bolter barrel. | 
| 
This chap is carrying a flamer, which you can't tell too well from 
this angle | 
| The plan with this one is to link the under-slung canister on the flamer to the large tank on his back by means of some type of pipe or tube or fuel line | 
 
 
