For metal and electronic music, I think you are not looking at quite the right speakers or subwoofer. I haven't heard the SVS speakers, but many who own them seem to enjoy them. The problem with them is the sensitivity spec is sooo low, especially for a bookshelf speaker with two 6" woofers. That means it won't play nearly as loud as ordinary speakers given the same amount of juice. And there is only so much juice they can take, so there is only so loud they can get. For this reason I also wouldn't pair those speakers with an Onkyo receiver, those receivers run hot enough under ordinary conditions, but now you might have to run the volume higher than normal because of the speakers. On the other hand, if you don't ordinarily listen to anything very loudly, I think the SVS speakers would do well.
If you like a speaker that can blaze, check out the Klipsch RB-61. Some other alternatives which are pretty highly regarded in the same price range are the Behringer 2030p Truth monitors, the Hsu HB-1 mk2, Infinity Primus p162 or p163, Ascend Acoustics CBM-170, and NHT Classic 2.
As for the subwoofer, if you need something smaller, the SB12 would be good, but again it doesn't get nearly as loud as some others in the same price range. I think for what you listen to, the SVS PB12 would be much better. The
Outlaw Audio LFM-1 EX is on sale this week for $549 shipped, it has comparable performance with the PB12 NSD, and will have much more output than the SB12.