I have a fluval chi on my desk, and absolutely love it, extremely "CHI" promoting with the little fountain/filter box in the middle on top. I will not lie I have heard problems about the filters later in their lives, I can definitely see this as a possibility, but its made up for in sleekness. I have already added a submersible internal filter and filled it with charcoal and bioballs for extra filtration as I plan on housing a messy puffer, but I am sure the filter it comes with does enough on its own for a few small fish. (if you do go with a chi make sure to buy a cover for it, you tend to get a wee bit of splash from time to time as its open top). The chi can grow plants that are right under the filter box but anything to the edges of the tank are going to be devoid of light, and this is a low light scenario in the middle at best.
I have heard the fluval edge has poor quality lighting as well, luckily there are MANY additional lighting options for any tank, as most of the aquarium kits have poor lighting. I went ahead and ordered some linkable LED modules, and am going to put a 4-led square on each corner of my square lid, to finally actually get some plant growth. This is very very cheap, and I was even able to get a remote system so I can control the color spectrum and light intensity! Or you can run a clip on light to most tanks, sitting next to a tank, if you are trying to grow specific plants.
I too have begun exploring the wonderful world of tank building. It is not difficult to do, and with DIY lighting, you can literally turn out a new tank with INSANE lighting effects, for next to nothing!
What temperature do they keep your office at, and is it a constant temperature or does it fluctuate?