Mr.lizzard,
I am not sure about the Marlin model you mention. I have had a few Marlins and I certainly have nothing bad to say about them. I had three of their rimfires and they were good, solid, accurate guns, but with very stiff triggers. I believe they were a 15Y (?) single shot, and a 781, 782(?) .22LR and .22WMR. I swapped them off several years ago when I didn't think I "needed" them anymore.
Now I have a nephew who is old enough to begin shooting and I recently bought him a Savage Cub to start out with. What I like about the Cub: Reasonably priced, good quality, Savage accuracy, comes with nice aperature sight, but also grooved for a scope (to be added later-maybe), Accu-trigger (adjustable, gives him a better chance to be more accurate, and is a very SAFE trigger mechanism), and the rifle is sized nicely for a younger shooter. I also really like a single-shot. I think it develops a better shooting mentality for a beginner. Also, no magazines with a forgotten round left in them, etc. I have been really pleased with the Savage Cub. The Accu-trigger was a big selling point for me. I also like NEF single shots as well - great triggers, very accurate, and safe. Also youth stocks can be replaced with full size later if you wish, and other RF barrels could be added if desired. All in all though, I would have to pick the Savage Cub.
One of the rewards of getting old (with all these aches and pains) is getting to get a rifle for a grandson. I hope you and he have a great time!