I have Fear and Faith, and I like it. Someone already statted a bunch of Lovecraftian entities, and they are available online, I think at Board Game Geek. Flying Lead is the same game system with military and police engagements in mind, if you need additional rules and stats.
Another option is Savage Worlds Showdown, the skirmish miniatures rules for the Savage Worlds RPG. The showdown rules were available for free at one point (not sure if they still are). They don't include Lovecraftian entity stats, but you can get those from Achtung! Cthulhu (as it is dual statted) or the Savage Worlds Realms of Cthulhu supplement.
I did up stats for the old Battleground World War 2 rules at one point (inspired by their tongue-in-cheek troll supplement).
Over in the BRP forums there is a BRP Warhammer 40K conversion. I haven't downloaded to see what part of it is inspired by 40K and what part by BRP (as I just found out about it). A conversation I read suggested that it took miniatures concepts from 40K and used BRP for combat resolution, but don't quote me on it. If so, though, it could be adapted to Call of Cthulhu stats.