These guys are look fantastic, and lets be honest, its hard not to want to start a Death Guard army with guys like these running around. A cataphractii terminator squad using alchemical weapons just is just fun.
These combined with Deathshround Terminators would look fantastic in any collection and on the tabletop.
These are available now from Forgeworld, just follow the link
http://www.forgeworld.co.uk/New_Stuff/DEATH_GUARD_GRAVE_WARDEN_TERMINATORS.html
Alone among the Legiones Astartes, the Death Guard make free and frequent use of alchemical weapons. These are deployed by specialised units outfitted in modified Cataphractii Terminator Armour; the Grave Wardens being the most renowned and feared of these harbingers of death.
"Pain is an illusion of the senses, fear an illusion of the mind, beyond these only death waits as silent judge o'er all" -The Primarch Mortarian