My sons (12 & 13) are new to Warhammer and want to start playing 40K with Chaos Space Marines and Blood Angels. 

We already have the free 'Warhammer 40,000 Battle Primer' but need to know what else we need.

I thought that we'd just need the new 8th edition Space Marines and Chaos Space Marines codexes, but I understand that Blood Angels need their own codex which isn't out yet. (BAs are apparently 'non-codex', which I don't understand as we are not very knowledgeable of 40K lore and history).

**Q. \*\*What rules/books do we need to play from the following list?:**

* 280-page hardback rulebook
* Index: Imperium 1
* Codex: Chaos Space Marines
* Codex: Space Marines

or would we be better of getting either of the 'Know No Fear' or 'Dark Imperium' sets (we already have lots of miniatures, as well as older mini-rulebooks and both Chaos and Space Marine codexes)