Most songs are too long for ringtones. If you want something rock/metal, but don't seem to want vocals (harsh/clean.) You could do what I did, and just have some instrumental section be your ringtone. I have the long and badass guitar solo for ANGEL OF SALVATION - GALNERYUS as my current ringtone. Basically since I got my phone...

Just youtube to mp3 a song you like, and insert it in some ringtone maker. (Or buy it, because Pirating is wrong and stuff.)  

[url=https://www.youtube.com/watch?v=nsi9HEmZl9Y&t=4m22s]Solo In Question[/url]