Hi Enigma-96,
We've all been New to this at some point Enigma, so no worries.
You may want to try Greenstuff for your rubric marines. I've never tried Greenstuff but some of the guys on TacCom can get some amazing detail on 6mm minis with the stuff, good luck.
I tried doing a search in the Epic 6mm Topic for Tzeentch and got these results...
http://www.tacticalwargames.net/forums....9bf9effHave fun looking through them.
I don't remember who did them but I do believe I have seen some excellent Silver Towers and Warp Palaces on here somewhere. I may have even saved them and can attach them here...
Hope this helps.