You might want to try asking speaker questions in the "speakers and subwoofers" section....not all persons read all the threads.
I personally would go with identical speakers if possible, or at least speakers in the same "family" that use the same drivers and were meant to work together.
As for moutning, compare the rated load of the mount to the speaker, and find a mount that will handle comfortably more than the actual weight of the speaker. simple enough!
