I just checked the specs for my Nexus One. The UMTS bands (3G) that it supports are 850, 1900 and 2100 MHz. 2100 is used elsewhere and 850 & 1900 are used by Rogers, Bell and Telus. The same model phone can be used on any of those three carriers. They also have a similar model which uses 900, AWS and 2100. (900 is used elsewhere). The 1700 MHz AWS band is used by Wind and so that phone is not usable on Bell, Telus or Rogers. 800 & 850 refer to the same band, so you're fine on Telus with it.I call Telus requested the WCDMA/HSPA frequency they are using but told are 800 mhz and 1900 Mhz.
You'll find Android works well. Which version comes with that phone?