I started my two sons and my brother in law on the Three Forks 3 wt.that was about a dozen or more years ago so I don't know if it is the same rod as then.theylearned on the SNP streams and small south central PA. streams and the rod was perfect for what you might be fishing ,given your location. just put decent line on the reel..if you can find something nice and inexpensive at your local fly shop go with them instead, if you can. it will be a better investment in the long run.i wasn't close to any when I started my kids so was forced to go online.
have fun and be patient.
'you 're really guiding rather than fishing with your son for the first year or so.
Best,
Steve