If you plan on speakers where you think you might add a sub, now or future:
make it Plural, plan on two subs, plan space so they can be forward facing adjacent to the main speakers, I say no port for the mains or subs, but if port, forward facing.
Low bass may start Mono, but the overtones become directional. 40/80/160/320/ ....There is a lot to be said for Stereo Bass. I listen to a pair of 15" woofers (1/side), the imaging of bass players is important and enjoyable..