How about a hw57? Before I get struck down, i bought one for my lad around a similar age. Theres nothing worst than having to pass to dad to cock and load, the 57 is easy to cock and the cocking lever is returned straight away so much safer for obvious reasons. Great open sights so he can go old school. Ambi stock for you both. Found his very accurate with no breech issues. Similar weight to a 99.