I'm not sure how to run things mechanically. As much as I love BRP, I'm not sure how well suited it is to a forum game. I'd think that a mechanically simpler game would be better, one that might lend itself to a mix of "salesman" and dice rolling.
There are dice servers we could use, but that adds an extra step to playing the game.
I'm also have a hard time deciding on a time period. I reread
The Case of Charles Dexter Ward recently, which spurred my interest in running/playing a game set somewhere between 1750 and 1800. On the other hand, it would be much simpler to run something a little closer to the present. I'm not sure that I want to commit to the reading it would take for me to feel comfortable running a colonial game. I bought a copy of the True20 version of
Colonial Gothic, but that just made me more curious about random and irrelevant bits of historical trivia.
EDIT: Here is the

to the BRP quick start rules. Here is a direct to CoC quick start PDF. It looks like whatever edition was out in 2004. Fortunately, the different editions are almost entirely compatible.