You definitely don't want that one. 900 Mhz, and 2100 Mhz are used in Europe, not North America. For North America, you want a minimum of 850/1900 Mhz. This will give you the best mobility between networks in
North America. Don't even worry about the others unless you plan on going to Europe anytime soon.
When the Telus rep told you 800/1900 Mhz, that's the same thing as 850/1900 Mhz, so do as the cust svc rep
told you.