Bike Forums - Commuting Singlespeed from Bikesdirect.com?

This is the first time I am looking to purchase a bike online, and new to the forums.

I currently ride a 21-speed Specialized Crosstrail hybrid.
I like the bike, but seeing how I ride about 200-220km/week, mostly city streets, and the odd light trail, it is costing me far too much time/maintenance.
I am athletic enough to stay in one gear, and am looking for the following in a bike:

- Low maintenance/extremely reliable
- Quality components that will last me as long as possible
- Durable; extremely strong for city riding
- Fast; I require speed to get to and from places quickly – a sprocket set that would allow me to get as much speed a possible, but at the same time to be able to use my muscles to go up a hill.

I’m basically looking for something similar to what bike couriers ride; single gear, very light/fast.

Can you please help guide me into the right direction please?
I live in Canada, and was planning on getting on getting it delivered close to the border then driving over and picking it up.
If there is a Toronto/Canada online store/shop one would recommend, I'm obviously open to that too.

According to the site, these are the ones that would fit my needs:
http://www.bikesdirect.com/products/trackbikes.htm