For the rooms in the pictured I would go with bookshelves. You already have the speakers and I assume they have a good enough bass response to get into the 60hz range so most good subs would pair well with them. I would suggest putting them on a pedestal or shelf of some kind to get them up to ear level. You will notice a difference, tweeters sound best with a direct line to the ear hole lol. If you did add pedestals they would waste just as much space as a floor standing speaker but without has much low end bass. If you put them on a shelf then you would get the same effect plus has shelve space
I think those rooms are going to be poor acoustic environments, a room makes a huge difference on how speakers sound. I'm not an expert but the crazy people in the Audio section of AVS forums are and I have learned a lot from them .
My living room has floor standers and bookshelves. Nothing special, just some Sony SS series speakers, they are easy to listen to and very clear but I still feel the need to use them with a sub.
What concerns me is pairing a sub with powered speakers is a little more of a challenge but is doable.
I prefer passive speakers after my active M-Audio monitors amp took a crap. Now they are utterly useless, if they had been passive I just would have found a new amp and moved on.
Floor standing speaker definetly can handle more power but my Cervin Vega HT6 bookshelves put out more volume than anyone should be anywhere near. They are capable of insane volume at low wattage, I have never maxed them out because the one time I tried my ears rung for a few days. They don't put out much bass though and pair well with a subwoofer.