I would absolutely recommend the evolution. I have it on the bridge on an ibanez GAX 70 and it sounds great. I use it in combination with the dimarzio FRED. The Fred gives you the fat sound that the evolution doesnt give as much. The dimarzio site gives you sound clips and specs on all their pickups do so research if anything for yourself but the evolution sounds great. And i play metal myself. As for F spaced that just means the distance of the magnets from the strings. If you have a floating bridge like the floyd rose on your guitar you will probably want the pickups to be F-spaced. If you have a normal bridge than you are fine. Hope this helps.