Is the fan dying? Is the heatsink clogged with dust?
Overheating with reference cooling (AFAIK, all eVGA cards use reference coolr designs) should not be a problem unless something is going bad, or you have really bad air flow. If air flow is the problem, then a shiny (really, they look a lot better than in the pictures

) new Zalman won't help much--it may extend the overheat time, but that's it. If something is going bad or has gone bad, it would be a great replacement.
Oh, yeah, being in Canada, try over at bit-tech.net. I could swear one of their forum stickies had online shops in various countries.
The Thermaltake coolers are fine. Try something like the Zalman flower or a nV Silencer, though, because if you don't have extremely good air flow, the big heatpipe ones are either going to be very loud, very poor performers, or both. I have a passive 5900XT, and it took some work to get it there. Also, the nicer heatpipe coolers take a lot of patience--you'll wish you have four hands, whether you use a fan or not. If you're up for it, the Zalman ZM80C and Thermaltake Schooner should be able to do the job.
The Zalman flower card cooler is not small (it's 4.9" at it's widest point!). Look at Leadtech's standard cooler for a small one. It work great, and the hot air then cools the RAM, too.
pic, via google, of VF700 installed