What you are suggesting sounds like the HERO 5th edition. It is black with silver and green print and a green HERO symbol right in the middle. While it is not bad, I actually wouldn't do that for BRP.
I also would not copy the D&D model and go with a faux book cover. You know, printing a picture on the book so that the book looks like a... well... fancier book.
I think a little artwork on the front would be good, but maybe it shouldn't take up the whole cover. Have it be more of a framed look, maybe with a large Chaosium symbol on there as well and the name printed at the top.
Oh well, I'd buy it if it depicted a steaming pile of crap on the cover, so I may not be the best authority.
