right. we need stats, a link would be nice.
The only reason I would highly suggest the alums is because of their VC configuration, you could wire them down to 1 ohm exactly. And I wouldnt really worry about them breaking inverted, theyre not exactly that flimsy. Plus i've actually heard half-decent things about the alum series as opposed to their other lower-line woofers.
But if you do want to go with the others, try to find either a set of 2 ohm DVC or 4 ohm SCV subs, that way you can get a 1.33 ohm load and still get plenty of power out of any amp you decide on.