Here is what I will do if I have to run a heroic fantasy campaign someday:
Rules Grim Tales, but non-spellcasting classes from D&D and a few other books (AU for example) will be allowed (but without action points, defense bonuses, and free multiclassing). Then, as the info on the gods is succinct, religion will be something Christian/Law like, so I will adapt much stuff from Medieval Player's Manual (Green Ronin), that should help me add a few new religious talents. Info on the Chaos gods is more detailed however, so they will be the Stanist equivalent of my campaign. I have otherwise WotC's Serpent Kingdom that will fit exceptionally well in the Lustria part of the world inhabited by Saurians / Lizardfolk.