Totem Arro or Sttaf or Hawk??

You didn't mention anything about your other equipment. I used to own a lot of totem speakers, including the arro's, model 1, and a couple pairs of mani 2's. I thought the arro's sounded great in my den with a low power jolida integrated amp. I used the model 1's in a room your size with Macintosh equipment. I added a Rel strata iii for the low end. I would recommend this setup in your room depending on your amp. I used to have floor standing speakers in the room before the model 1's and it was very hard to get the sound right. When implementing the Rel, it was very easy to get the bass right since it was adjustable. With the floor standers like the hawks(which are excellent speakers in a bigger room), you don't have the room to get the speakers out into the room since its on the smaller size.
Just my opinion.

You really need to tell us what amplifier you have. The impedance/sensitivity ratings of all three models are different with the Arro being the most difficult to drive; the Sttaf being the easiest. Everything else you provided, won't matter if the amp is not up to the job first in properly driving a loudspeaker.

Next, the Arro and Sttaf use soft dome tweeters and the Hawk uses a metal one. Big difference in how they sound. One is not better than the other - it comes down to preference. So once we answer the amp question, suggest you audition all three models to find the one that sounds best to you.

All of them need big power except Forrest that has advantages of all three combined IMHO.
1. No need for large power
2. Stable load impedance
3. deeper bass
4. deeper soundstage

I can support what Paraneer and Czarivey have said,

My room is about the same size and I use Arro's with a Storm subwoofer. If you don't listen to bass heavy music (I listen to a lot of Metal), you could probably do without the Storm. Fortunately, I had the occasion to audition all three of those speakers side by side (during a demonstration by Totem's Vince Bruzzese no less) and I preferred the Arros.

I used a Simaudio Moon i-5 with the Arros and it was competent, but they really showed their best when I upped the amplification with my Magnum Dynalab MD-209.

I've had the Arros and Forests simultaneously in a prior system.

First and foremost both needed a significant amp grunt (high current and watts) to perform at their max.

However I strongly disagree with the comment that the Forests are easier to drive: quite the opposite in fact.

I had an all Arcam FMJ system that was a bi-amped kit to get the Forests to perform at their best. by contrast, The Arros were not bi amped by comparison, and I second the suggestion that a Simaudio I5 would be a nice match.