2nd Army Ideas

After Orks are complete I'm thinking of a second army. In the event the winner is unable to fulfill her duties as Army the second will take her place...

I want to do a mechanized army, my ideas and suggestions from various forums include:
Mech Tau - do Mech well, but somewhat cheezy
Kult of Speed - do mech well, but i have an ork army
Sisters of Battle - would be fun to get all those flamers in close via rhino transport
Space Marines - Black Templars and Blood Angels bing my only options, Blood Angels are out as there's a BA player already.
IG - too model-heavy
Chaos - Access to rhinos, plus the Daemon Bomb!


I think at this point I'm gonna pick up the Chaos codex and read up on them. I LOVE the pic in the rulebook on pg. 128 showing the Word Bearer. almost definitely would go with a word-bearer daemon bombers. Bikes and rhino mounted marines, roll up, get out, pop the bomb. let the fun ensue.