JUST FOUND THIS ON EBAY, DIDN'T REALISE THAT THERE WERE RULES FOR GREY KNIGHTS IN BFG!!!
Painted, Based & Varnished Black Ship and Escort Fleet
Contains: One Grey Knights Strike Cruiser (Forge World), 3 Gladius Class Imperial Fists Frigates (Forge World), One Imperial Fists Strike Cruiser, and one unique converted Black Ship, all expertly painted in one of the more popular colour schemes, and varnished in satin varnish. All these ships have been painted using the layering technique, with 5 coats of paint to achieve the depth required.
The Black Ships are terrible, nightmarish transports filled with screaming psykers held in cavernous, psi-shielded holds to be taken back to Terra to feed the voracious psychic appetite of the Emperor of Mankind. They are ancient, pitted behemoths that are used to collect all the potential psykers found by the Imperium and carry them back to Terra. Here they are fed into the choir that maintains the Astronomicon, or become soul-bound to the Emperor and used in the service of the Imperium. Such a precious cargo requires a powerful escort, hence the presence of the Imperial Fists and the Grey Knights!
Train hard, fight easy.