First of all, going to cop out on/delay Black Templars, Blood Angels, and Dark Angels. I'm not really familiar with BT or DA, and with the BA getting a new book soon I think I'll leave them at least until after their release.
So, skipping those for now, we get to Space Wolves! For full counts-as impact with the SW I think you have to take advantage of the Thunderwolf cavalry, so that will definitely be a part here. We haven't done a squat army yet, so how about some Chaos Squats, with some WHFB Chaos Dwarf carryover? The hosts of the dark forge world Zharr come forth to battle for their master Hashut!
Bull Centaur Lord (Wolf Lord on Thunderwolf)
-Should probably be made more impressive than the regular Bull Centaurs, further along in mutation/closer to Daemon Prince status.
Sorceror (Rune Priest)
Forge Master (Iron Priest)
-with option for mechano-centaur body (Thunderwolf)
Immortals (Wolf Guard)
-Normally fielded in exo-armor (terminator) squads, can also be used to bolster other units.
H'gob Scouts (Wolf Scouts)
-Xenos auxiliaries, the H'Gob are real sneaky gits, able to take up good battlefield positions/surround the enemy while the main forces of Hashut move to the kill.
-Daemon Engine warbot, capable of dishing out good firepower as well as close combat destruction.
Warriors of Hashut (Grey Hunters)
-Power armored Chaos Squats.
Bull Centaurs (Thunder Wolf Cavalry)
-Good ol' half-bull Chaos Dwarves, this time in power armor.
Planetquakers (Long Fangs)
-Power armored dudes with heavy weapons. Since everyone has guns, this is the crossover for the old blunderbuss-using Chaos Dwarves.
Tanks (various tanks)
-Having access to at least one forge world, able to have a variety of armored vehicles. Any would work, though I think Whirlwinds and Vindicators would fit the old Chaos Dwarf imagery of chukking rockets and artillery around the best.