I am presently building two units of 5 Black Knights a Wight King and mounted Vampire. Used one box of Empire Knights, heads and shields from Grave Guard, one box of Empire General/standard set, bits from Flagellant set, corpse cart, zombies, and ghouls, plus three spare horses with the old metal chaos steed heads. They were great fun to build and are presently half painted.
One tip, if using Grave Guard heads on Empire knights, build a little spine in the hole for the head to raise the Grave Guard heads a little or they look like they have no neck, not a good look at all! Just use bits of spare spear shafts or the rope bound bits on the zombie standard.
I'll post some piccies when they're finished and when I figure out how to post them. In fact I should post a little blog thing as I only started this army in October, done 80 Ghouls, 3 Spirit Hosts and 10 Dire Wolves, not as much as I had hoped but been doing alot of commission work too, sigh!
Take care
warpaintjj