Well, this thread is really dying...I'll try to bring back some life here.
With Dragonite, we obviously need a way to switch into and dispose of steels. I'm not very fond of Magnezone, so I'd like to suggest a fire type, Heatran. Heatran can easily switch into most steels for Dragonite and threaten them, while benefiting from Forretress's spinning due to lack of recovery. Furthermore, the type synergy with Dragonite is terrific, resisting all of each others weaknesses except for Dragonite's rock weakness. Of those resisted weaknesses, two jump into the eye: D-Nite Being immune to Tran's 4x ground weakness and Tran 4x resisting D-Nite's 4x Ice weakness.
I just feel an offensive Heatran would fit nicely for an attacking core with Dragonite, but I don't really know what set I should post. It could be offensive with Leftovers, Life Orb (hard to make a good bulky offense with that) or Choice Specs (which benefits even more from spin support). Without further ado, here is the Smogon Analysis's Specs Heatran set:
Heatran @Choice Specs
252SpA/4SpD/252Spe
Modest nature
~ Fire Blast
~ Earth Power
~ Dragon Pulse
~ Hidden Power Grass