What is the best set of speakers for my Onkyo Tx-nr545? Made by _____
This is the wrong question!
Onkyo makes a good AVR, and just like Marantz, Yamaha, Denon, Pioneer, etc, your AVR will amplify the signal fed into it without adding or subtracting anything audible (which would show as high levels of distortion). They have been doing this since the early 70's (if not the late 60's). Any notion of a specific brand having a specific character is poppycock and the purview of audio magazine authors attempting to generate interest in products sold by the companies that advertise (indirectly pay their salary). Tone controls or EQ systems may work differently, but the basic sound without added tone effects is very consistent.
So your question should now be "What are the best speakers to get?"
I don't know how patient you are (or how important this is to you),but if you could find a local Audio shop to listen to some speakers and come back with your impressions, that would be a good starting point.
You are in Canada and I am not certain how much that restricts you as far as availability.
PSB and Paradigm are a couple of good CA made options!