Before you buy anything or change modems, you should try forwarding the port that you use to torrent, directly to your computer if you haven't already done so.
If you do decide to change up, I agree with you on the WRT54GL. There's so many good custom firmwares out there for that specific model.
If you need a cheap bridging modem this should do it.
TP-LINK TD-8816 EXTERNAL ADSL2/2 MODEM + Ethernet Router - TD-8816
I personally use the above TP-LINK modem with a WRT54GL router modified to the Tomato custom firmware.
The custom firmwares for the WRT54GL allow you great control over your modem. And Tomato is extremely easy to use. It has a Quality of Service option which sounds like something that would help you in your situation. It's also apparently easy to use (I don't use the QoS though, its confusing as heck to me lol, but my speeds are still great).
A bonus is that you can enable mlppp, which bypasses the throttling through my ISP.
I don't know much about Telus, if they support mlppp of if they even throttle your internet. But from your description, it does sound like they are throttling your internet.
Just a question, how fast do your downloads from fast websites go, and how fast do your torrent downloads go?
My current setup with Teksavvy (some people on these forums and RFD recommened them to me) can dl torrents at a constant 350kb/s if well seeded. It downloads from fast websites at 300-400. and 200gb bandwidth limit a month, all for $30 a month.
If your interested in a similar setup heres a link to the thread that helped me
Beat Bells throttle via mlppp and a compatible wrt54gx series router. - RedFlagDeals.com Forums
Also, sorry for getting off topic lol.