Thanks for the great reply, jmac - I think I'm still hooked on the 2 subs + 2 amps idea, though, I got a 200 amp alternator upgrade and a yellow top battery under the hood now, so I think the power consumption will be ok? If if it's too much, well, I guess I'll have to remove a sub & an amp and give them to a friend ...
I spoke to Nick at SI and his suggestion was to "to wire up each Magnum for a 1 Ohm load (in parallel), but keep the gain turned down a bit", and also to make sure the enclosure was tuned to the right frequency. That, according to him, would be pretty kick-***.
Like you said, I'm relatively new to this thing, so I'll definitely get professional help (probably VIP Motorwerks in Millbrae) for the install / enclosures / dampening (yes, lots of sound dampening will be needed, I believe). I might try to do the kick panels myself, but that's as far as I will go //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif
Thanks again.