Custodes and Sisters of Silence.

[Haighus]

Well, the way the formation is called a Golden Host Task Force suggests to me that the Custodes have begun sending units abroad on specific missions deemed of critical importance, no doubt under the direction of some cadre of psychic prognosticators in the Imperial Palace. After all, the events of the 41st Millennium are becoming as dire as the Horus Heresy.

The snippets of fluff for the Sisters of Silence suggest that their remaining members roam the galaxy at will, hunting down and destroying witches and warp-spawn who they presumably deem of great threat to the Emperor. Which I think is pretty damn awesome, like warrior-assassin-nomads.

[Jmaximum]

My memory is a little flubbed, but I vaguely recall the Custodes had miniatures back in the rogue trader days, in full armor.

[grimmas]

This is the Rogue Trader minature and fluff drawing from Rogue Trader





Though having read Master of Mankind I'm really glad they've been brought back in their fully armoured form as they're freaking great.

The original Grey Kight Terminators did look quite similar to Custodes their Nemesis force weapons looked just like the Custodes Guardian Spears



No pointy heads though

[Jmaximum]

Maybe I was thinking of those craptastic grey knight terminator abomination minis with the guardian spears....