Hi, I am planing to build a pair of 4343 speaker but I have hard time finding the 10" mid range and the network. beside the 2121, I don't know what other 10" midrange can be replace? I realy like the sound of the 2121. Also, I can not find 4343 network but I found set of 4345 network availble. Are the 4343 and 4345 network the same? If anyone have the diagram available, please send me a diagram of both so I can compare.