I’m trying to manage a system of 3 sets of JBL 4670D’s + an unknown but probably JBL subwoofer. Does anyone know about the 4670D’s?

They seem to be highly sensitive (although they probably need more than 2 watts lol). Right now they are being powered by 3 QSC USA 1310’s and an old Marantz A/V Receiver.

Where are my bottlenecks? What do I need to upgrade first and does anyone have suggestions for A/V Receivers and home theater amplifiers etc.? Also, how much power do you think I need for these? Budget is in the 4-7.5K range. 

Thank you so much