Why don't you consider getting a pair of Paul Speltz of Anit-Cable fame's new Auto-Formers. These would bring the impedance created by two 4 ohm speakers in parrell resulting in a 2 ohm load that the amp would see, back up to 4,6 or even 8 ohms depending on which taps you use. Another option for you. Also some of the early multi speaker boxes from Niles allowed you to hook up up to four speakers while maintaining the proper impedance by pushing the correct setting on the box for "multiple speakers" attached.
Marantz 2325's interaction with 4 speakers/load?
I am bidding on a Marantz 2325 amp, and want to know can I drive my Thor speakers (like 6 ohm, I think) on one set of outs and with the other speaker outs run a pair of Seas W26's as woofers(has a proper xover). Will this load damage the amp over time? are the Marantz's built "like a tank", so no problem?? I wish to see how much more dynamics I can get out of the Thors with the Marantz, vs the little Jadis Orchestra intergrated. I use to have a Marantz 2015, for a little guy, sure was nice sound. I recall there was talk back in the 70's that the 2265/2250 was more musical vs the bigger Marantz's. True?