Troll Heavies - Where to Start?

So I am going to get for my Trolls a heavy finally. There are, at least by my count, 4 different Heavy Beasts. I am basing all this on Battle College's Trollblood Page so forgive me if I am not stating the right things.

Firstly we have the Dire Troll Mauler. A staple it seems of alot of forces, his animus Rage gives a trollblood model +3 STR for one turn. He also has a fury of 5 and a decent P+S Attack on his 2 fists, plus his chain attack. Snacking also seems like a decent way to keep him alive, but I have heard that he can be downed easily with focused fire.

Next, we have the Dire Troll Blitzer. His animus seems situational, and while he doesn't have the chain attack he has a d3 Gun that can fire regardless of what the troll is doing. Run the troll, fire the gun. In Melee? Fire the gun, but at a target NOT in melee with the Troll. The range is meh, and so is the RAT, but the Impaler at least can boost the Ranger and I am not sure if the Fel Caller can boost the RAT (I don't think it can).

Thirdly, we have the Alpha Beast, The Earthborn Dire Troll. He is slightly easier to hit but also has a better MAT then the standard Dire Troll, and his Animus is interesting. I hear alot about "double dipping" to get the KSB Armor Boost twice using his Animus. His special powers seem interesting on the surface, and since I have been enjoying Grim I could see a few combo's with Grim and the EBDT. Also the Stealing of a Weapons POW can be devestating but I wish I knew more about how it worked.

Finally, we have the big daddy, the oldest of all the Dire Trolls....Mulg the Ancient. This guy is our character beast, and truth be told I love the look of him. He is so...angry and awesome. In fact, he is one of the first reasons I started looking into Trolls. This guy just screams BEAT FACE NOW! His animus is interesting, and his special Rune Breaker Scars are also interesting. He has reach, which is neat, but only 1 really powerful hit and then a secondary hit in the open fist. Since I am not running Doomshaper his affinity is moot, but Are you going to Eat That seems amazing. 4 inches of out of turn movement + regeneration? Sign me up man! That could be scary.

So here is where I stand. I want to get 1 single heavy for now. I am limiting my purchases to one item for Hordes a month, and for now I want a heavy. I just have no idea what to GO with. I have Grim and Madrak for my casters, so I want something that can support both of them. I am leaning towards either the standard Dire or the EBDT, but Mulg just looks so awesome. Of course, conversly, Mulg is the most expensive of the brutes. Comically enough I have a guy who wants to paint Mulg when I get him for free, so I do have that if I get Mulg hehe.

So I ask you all, the paragons of Warmahordes! Given my options which Heavy would YOU start with and why?