Your idea of butternut I would say to toss, it's not hard and like I told you earlier today on the phone it makes good canoe paddles since it's so light and not dense. Personally I like maple bodies for your type of music, I like the brightness of it when I mix it with my pedal board since I can get a nice clarity on the notes but use my pedals to get the lowness you need (I use a digitech grunge for distortion).
I have a cousin in Finland who just made a neckthrough that was completely maple and he plays stuff like Ozzy and that type so there is your option there. Have you looked into using Oak at all? I know a guy who uses red oak on acoustics for the back and sides and then uses a Norwegien Pine soundbaord, that combo has a pretty good high and low reponse which you might like as well.
As to using rosewood I would highly not recomend it. In my experience and in the above mentioned luthier we both don't like it. It is very unstable, meaning it does not handle temperature changes like we get in Minnesota well. It will twist and warp easily unless you can build it and finish it in the same tempurature and humidity. And for fretboards try to find a way to seal it because the frets will move like with any wood but it seems that with rosewood it's the worst.
I use birch quite a bit as well and I like the result I can get from it, plus I'm sure you can get a lot over where you live. All in all I would say just test things out and see what you like and if you don't like it sell it and start over it's as simple as that.