6wt is a good choice, though I used a 5wt as my only rod for years including on the Bow, and it was perfect for rivers like the Highwood, Sheep, Crowsnest, etc.
If you are a one rod fly fisher in southern Alberta, its basically either a 5 or a 6. Pick which one you want first. Eventually you'll buy both
LOL
Make sure that whatever shop you go to, you test many many rods of both weights in the parking lot at least. If they won't let you, move on. Some rods you just cast much better than others. Someone here may recommend one particular rod, but for you it's not optimal.