I think the options for the Canadians are nuclears or Collins II.
Honestly I think Collins II would be a better go for them, get in at the ground level, get something that meets needs and requirements. Have a partner that is going to be helping and paying for upgrades, improvements, fixes. A partner that gets along very well with the US.
The o-boats were such great boats I can see why people thought the upholders would be again, awesome boats. But even the o-boats had signficant problems early on and it took at lot of development and time to get them to a capable level. Its just that it was shared between all Oboat users (usually). You can pretty much say that about every submarine (US just has the $'s and the hulls to make it seems easy).
Why didn't canada concider (well the article puts it this way) Collins? They could have been built in Canada, again shared systems, US support etc.
Collins was expensive, but we got something out of it. Upholders are on the level of seasprites where you get essentially nothing on your investments. I can't belive they paid $750m back in 98 given they had a rough idea of how much work was to go into them (lots!). For the money they spent (all up)they could have got 4 Collins subs, and have 1 avalible most of the time and still have a fair amount of life in them, and a partner to develop with. Instead they went alone with orphaned systems and ships.