Again, lots of variables...
What is the main purpose of your speakers?
Mostly music?
Mostly movies?
50% / 50% or higher percentage of music/movies?
Basically, book shelf speakers are your best bang for the buck however, if you consider your self a critical audiophile, you might prefer floor standing.
Floor standing speakers will usally offer larger and/or more drivers and potentially cover lower bass frequencies. However, my concern is that drivers are so small nowadays even in floor standing speakers that I wonder how is the SQ of such even in towers. You look for example at the M-10 and M-20s from Polk, as far as I am concerned the only advantage of choosing the floor standing would more likely be that you do not need stands for them
Now, you are mentionning the Tsi series which is a really nice speaker and here are the specs for both of them;
http://www.polkaudio.com/homeaudio/tsi/specs.php#bookshelf
http://www.polkaudio.com/homeaudio/tsi/specs.php#floorstanding
You should have noticed that the bookshelf (Tsi 200 and the TSi 300) share the exact same drivers and that the frequency rating and power efficiency are mighty close and the main reason is that there was no addition of any complement driver dedicated for the low end. If you were to step up for the Tsi 500, then the efficiency is little more significant since they use larger drivers along with the addition of an extra driver (however not dedicated).
However, if you look at the old Monitor series you might not get the spiffy look of the Tsi but you get the quality at a much lower price. This one has been proven for many years and are still your best bang for the buck. Look at the potential difference in efficiency between the largest Monitor bookshelf (Monitor 40) and the largest Floor Standing from the Monitor series (Monitor 70);
http://www.polkaudio.com/homeaudio/specs/recent/monitor40/
http://www.polkaudio.com/homeaudio/specs/recent/monitor70/
If you do your home work and take the time to use your favorite search engine (IE: google) you could find some great pricing in Canada.
The below link will provide you with a little more knowledge of speakers (old, 2004 but still apply nowadays);
http://www.peachpit.com/articles/article.aspx?p=355878