I have a DIY JBL-4350, mine are in a 6000 cu. ft music room with acoustical treatment on walls.
I am primarily into classical and some jazz.
Mine are powered with a pair of McIntosh MC2205's, these are 200W amplifiers. I normally listen with fairly loud volume but not loud enough to bleed my ears, generally speaking I have not been able to go above 40W, most of the time 20W from each amp is my safe limit.
The 4350's are 99dB above crossover point and are 96 dB sensitive for the low end, the dual woofers. Personally I see no reason for going with such hi power amps given the system sensitivity.
There is something visually attractive in combining monster speakers with monster power amps, but with 4350 you are wasting a lot of power and $$$ if you go for the looks.
And,
Good luck.