Howdy,
New guy here, I use fly gear exclusively now, and get out about 100 days a year.
A 5wt will work fine to handle that size of smallmouth, but you will run into problems casting wind resistant flies, such as poppers, into the wind with a 5wt line. You'll be better off with a 9', medium fast, or fast action 6wt and a Weight Forward Floating line. These guys were right about the reel, it just holds the line, and smallies aren't gonna take very long runs.
I don't have 10 posts here yet so I can't post links, but if you click on the link in my signature it will take you to my personal website(non commercial), On the Navigation bar on the top of the page there is a "How To" button, click it and check out the parts on choosing a fly rod/reel/ and line.(this isn't spam, I swear ;D)