Lore Question - Word Bearers / Sons of Horus and the Battle of Luna

[Testamentum_Veritas]

While I’m waiting for my Heresy starter set to arrive, I’ve been delving really deep into the lore I’ve missed over the past few years trying to catch up. 
This, in part, has been due to the challenges MkVI has given me with finding a theme. 

I know I want Word Bearers, and I know I want to use the new models. So to outfit them in MkVI the army needs to be set in the late Heresy. Which to me means Solar Wars to the Siege of Terra. I know I’ve missed a lot of lore in the last few years, so started my research on these topics to identify key events the Word Bearers took part in. 
The most interesting bit I found was a joint operation between the Word Bearers and Sons of Horus to capture Luna. This has set my theme nicely as the Word Bearers are the Unspeaking led by Zardu Layak and leaves options open for Sons of Horus allies. Love this. 

Only problem I’m having is the quality of info on the 40k wiki. 
I’m used to these being direct copies of the incredible black book lore, making it much easier to find what I need from a quick search. In this instance, I’m left with vague and often badly written summaries of the Siege of Terra novels which is making my job a lot harder. 
So for those who know this part of the lore, or can reference the appropriate novel I would love a bit more info on this event. Specifically: 

What are the key events of this battle?

Was the battle on Luna’s surface a real battle with tanks and infantry etc.? 

When it says surface, do they mean the actual surface of the moon? So I can make awesome moon bases. 

Thanks everyone!

[sarabando]

mk6 armour was fielded during the great crusade so its fine to use for any time frame. The luna war was a lot of fighting through hab cities and gene labs iirc