Stand-mount speaker recommendations

I have recently switched from a little British system (Croft/Harbeth) to Van Alstine separates for amplification. The upgrade in clarity and power (300wpc) is significant, and my little Harbeth P3esrs are not quite enough to fill my living room (about 12x16 feet with an open end). I was sitting much closer to the speakers, but now I’m back about 8.5 feet. I’d like some additional bass weight and a larger sound.  I have had bad luck with rear-ported speakers becoming boomy as the wall behind the speakers is fairly flimsy apartment construction and resonates even with acoustic panels. So, ideally I’d like a front-ported (or sealed) stand mount speaker that goes down to 50-45hz. If it goes much below that it can overwhelm the room. I am very sensitive to etched treble, extreme detail, sibilance, etc. (hence my choice of the P3s.). Budget is $2500 but could stretch a little if needed.  Any recommendations would be greatly appreciated!

Thanks,

Scott