There's a lesson in how the equipment works that needs taught here I believe. Subs don't "pull" power or put a "strain" on any amplifier. Now, that doesn't speak to the impedance the amp is seeing, I'm just referring to the fact that speakers are stupid. They do as they're told and are in no way an intelligent device that uses, pulls or requires power to operate. Now, if you wire any speaker(s) to any amp and the impedance is less than the amp is rated for it will stress the amp, but that has NOTHING to do with the wattage the speaker(s) are rated at. You can put a 10,000 watt speaker on a 1 watt amp and it won't stress that amp any worse than it would a 10,000 watt amp, it just won't get as loud obviously. As long as whatever subs you get have a final impedance that didn't go below 1 ohm it won't matter if they're rated for 300wrms or 2,000 wrms it's not going to stress the amp any differently at 1 ohm. And I'll admit I'm biased, go with Fi....