I am in the process of restoring some Marantz Imperial 8 (http://www.classic-audio.com/marantz/imp8.html) speakers for my dad. He wants a vintage setup. The reciever is a Marantz model 4140 (http://www.classic-audio.com/marantz/4140.html) The configuration is a 3 way crossover, with lows going to a single 12", mids going to three 3"s and highs going to 2 1"s. All of the drivers (except for the tweeters of course) have experienced bad foam rot. Where can I find suitable replacement drivers and what ohm will they need to be to result in an 8 ohm overall impedence? Thanks!