I'm not 100% sure that an HRV would give you the same bang for the buck in Vancouver or other milder and wetter climates as it would in say Alberta where it runs cold and dry for a goodly part of the year, so that's one thing you might want to check into. But, in answer to your question, if you're ripping out a furnace anyhow, adding a HRV would be only an incremental step. It's basically a box that sits somewhere near your furnace, it has 2 pair of ducts/vents (1 pair goes to the outside, the other pair goes to your furnace vents or to your room that you're targetting {or both}). So 4 vents in all.
One thing to consider if you're getting a new furnace anyhow: consider going "all the way" and get a "high efficiency" furnace (the more common ones are considered "mid efficiency").
A high efficiency furnaces uses a DC drive motor for the fan instead of AC and the cost savings is apparently enormous. For example, you can run your fan on all the time, and still pay less for heating than a mid-efficiency furnace who only turns on when needed. Having the fan on 24/7 can do a LOT to keep humidity in check because it's constantly cycling.
I wish someone had explained that to me when I put my furnace in. By the time I realized this about the furnaces (ie. the DC drives) it was too late and I had a mid-efficiency furnace put in. The cost upswing if you're buying a furnace anyhow is easier to take than the full purchased cost of a new one when your current furnace is too new to be replaced anyhow, so I'm sort of stuck. But that's why I thought I'd tell you - if you're looking at replacing a furnace regardless - then high efficiency is the way to go.
HTH