Great choice for a float rod. The longer the better. I have a STR1265C, I use it for everything from hog fall chinook to summer steelhead. I usually use it when the water is up and Im dealing with strong curren flows.
The 1263 is a better choice for steelhead. You should be happy with it. Built as aspinning rod you will be able to cast light wieghts with ease. I have a STR1143C and a STR1141C I use both for float fishing. I wish I had that extra foot sometimes for better line control.