Bookshelf + sub vs. floorstanding


I have room which I currently use 50% for music and 50% Home Theater (I wish I could split, but no way at the moment). The room is 15 x 21 x 10 feet and I'm working on some acoustic panels to help with overall image and definition. I'm looking forward to make an upgrade on my system, more specifically buying new speakers for left and right channel. The budget is $14,000 max. I see lot of people happy with bookshelf speakers, especially for their imaging and ability to "disappear". Main complain is the lack of bass. 
I'm considering buying a nice pair of bookshelf plus a pair of sub woofers, instead of going with classical floorstanding ones. I really like a sound stage "reproduction" and that "separation" of instruments. 
What would you recommend and why? 
fabifrac
It's actually very easy to get great sound from a sub or two, so don't pay much attention to anybody saying otherwise. Use subs that take the signal from the amp, like RELs or Vandys , and simply move the sub around and adjust the level. Not as head scratchingly difficult as many imply. Note that a good sub (I have 2 perfect "previously owned" RELs bought cheap) allows control over the bass simply by phase and level adjustments on the sub, and DSP in most cases is unnecessary and just adds electronic junk (and more cables to get in the way) to the signal...less is more, simple is better. A "full range" tower speaker generally doesn't allow the flexibility of bass control, and obviously doesn't allow for bass speaker placement free of the main speakers.
Floorstanders should give you more coherent sound, theoretically. Personally, I don't ever even think about subs for a relatively small room. You will of course need good source and electronics too, along with cables and wall current. $14k is pretty good, and if you consider used as well - great, you could have $45k speakers, maybe.
For home theater I much prefer having the sub no matter which way you go. Floor standers just won’t cut it for that epic movie bass. 
If speakers don't play low frequencies due to design, it doesn't matter how small the room is...a good sub can make a gigantic difference overall as it's not just the bass, but a "room charging" effect that makes music sound more lifelike through your main speakers. My smaller sub is an older model REL 8" downfiring (Q108 MKII) that by itself is amazing...and small.