I have the in-ceiling speakers and they sound great. I only have 9' ceilings but adding an amp would help if they didn't have sufficient sound at 14'.

LFR1100
VP180HP
EP600
M3 In Ceiling x 4
M5OW
M2 - Atmos rears
ADA1500.5
M3 Outdoor Speakers
ADA 1000.8