the Chi is 12"x10"
And I don't think the plants in the picture are real... I've no idea how the roots might interfere with the filter.
I'd say that a pair of Golden (I assume Golden Wonder) Killies would be overcrowding somewhat.. IME they always stayed at the surface and would swim around a bunch, so not really enough room for that, the bioload wouldn't be a problem I think though.
There are lots and lots and lots of nano fish that would be suitable, if Killies are your bag, try a school of Clown Killies.
At the end of the day it will depend where you're comfortable ordering from.. what options you have locally, if you don't mind having livestock shipped to you, then you have many many more options.
90% of my smaller fish came from
MsJinkzd I don't believe she ships to Canada, but you could try asking, and if not just poke around at some of the fish profiles on her site to get a few ideas.
Alternatively she and another AC member co-wrote a book on FW nano fish... sounds like it might be a useful read for you.
http://www.amazon.com/Best-Freshwater-Nano-Species-Invertebrates/dp/0982026250