CO2 Regulations in Canada

I've finally bitten the bullet and decided to set up a 
planted aquarium.  I've been researching the details of CO2
fertilization and have a bunch of questions.

1.  Someone told me that its a real hassle to get CO2
refills in Canada.  Has this been a problem for any one?  I
live in Toronto - if anyone knows of a good source I'd 
appreciate the tip.

2.  I know that most people out there are building their own
CO2 systems from cheap materials.  However, I'm willing to 
spend a bit to avoid the hassles.  I understand the Sandpoint's
Genesis II is a good system.  What is the difference between 
Genesis II and Genesis I?  Also, what is meant by a semi-
automatic system?  I assume this is more automatic than manual
or am I wrong.  Finally, if I do want to go automatic, has
Sandpoint rigged it so I have to use thoir contoller or will
any contoller work?

Thanks in advance.

Bryan Klompas