When it comes to Roswell, I always say my basement has the best beer selection, but I digress... The other tour option in Jekyll Brewing in Alpharetta is an easy combo with Hop Alley. They do tours almost every day, and while I don't like their naming convention, I do think they make solid beer. Less variety than Hop Alley, but more consistency.
In Roswell, Salt is pricey, but has a decent craft list, and within walking distance is Mac McGee's and Roux, which also both have decent craft options. Further down, you can do tasters at Ale Yeah!. While in town is optimal, as you say, old town Roswell might be a happy medium, offering some sociability/bar hopping and some craft beer...