The only empirically proven method discovered to date for providing very good bass response that is well dispersed throughout any given room is the use of a Distributed Bass Array (DBA) system.
<< cough cough>> Hahaha. Hahahah. Hahahahaha. Let's ignore all of the literature on the subject to date.
Getting good bass is no joke, and (DBA) has merits, but typically room acoustic treatment + EQ is the solution and yields very very good results when done properly.
When it comes to a large full range vs. Satellites+Sub, the best solutions are usually satellites + subs, BUT!!! What a pain to do right. I mean, there are technical advantages, in being able to place the sub separately, and being able to put an EQ in front of the sub without altering the mains, but it is a lot harder to do than just dropping a sub into the room.
My usual answer is get a really good 2 way. :) Mine are flat in-room to 25 Hz or so.
There is also the issue of loudness. If you have a receiver, having a loudness control is a really good thing at low volumes. Otherwise, you want a speaker with a smile-shaped response which will be great at low volumes, and then be uncomfortable at higher levels.
Denon used to have a wonderful loudness control for this.
Best,
E