Yeah, I have a future WE army planned for '07ish so that would be more Power Armor.
Looking across the 3 sites I posted this, it seems the Siege Regiment is preferred (not by much though). Most people think it is a cool idea for an army and have never heard of such a thing, that, and it is not a Marine army.
The cost factor is not really a concern. More so, the fun factor and that I would also be the first player in my area to ever have not only Guard, but an Armored Company.
I already have plans to apply those WW2 cute girl pictures you see on the planes, to my units, to give it some penache'. Paint on some grave stones that say R.I.P. on them to the gun barrels and really give this army some nice flavor.
I think seeing a bassie with some cute 1940's redhead in some skimpy skirt, holding an old "Coke" bottle or something, painted along the sides, would be pretty darn cool to have.
Hahaha! Brainstorm: I guess I will do both armies, AC now and DW after WE and non Res Orb/Monolith Necrons. ;D
If anyone else has some input to either DW or this Siege Regiment idea, post it up here.
Oh and thanks for the input thus far.