I've got an old chart for AF. Looks like the Burkie 8133 Scandi recommendation is 540 so a Rage in either 540 or 570 should be good depending on your casting style.

No info for the Sage One but I'd guess 420.

 

Thanks!

 

From Tom Laramer, the designer of the Rage Compact...

"To determine the correct weight to choose and as a general rule of thumb, line your rod 30 grains lighter than your Skagit Compact. If you like a faster-livelier feel to your floating head, go 60 grains lighter. Like all of Airflo’s Spey heads, the lines comes in 30 grain increments and are available in 360 grains to 600 grains."

So it's not recommended to go as light as the scandi weight for your rod, rather somewhere between skagit and sandi. But, as jason said above, rods these days have large grain windows and thus it really depends more on your casting style and ability.