A Mom who needs Help! - Finding a board for my son

Hi all, I am just a mom with no surfing experience trying to buy my son's first hardboard for his 10th birthday. We went to 12-15 shops today and rec'd differing opinions on what we shoudl buy. Here's the scoop. He is 48" tall and obout 90 lbs. He is a great skateboarder and snowboarder. He has surfed about 20 times in addition to some surf camps where he did very well from the getgo. Today he surfed on his first hardboard, a 6'2" fish with a swallowtail (Bioboard by Tom Nielson). Waves were quite small. It was 2 5/8" thick and 21 1/2" wide at the midpoint. I had four fins (if that matters). Today we were directed to anything from a 6'4" Fish by IslandSurf to a 5'6" Fish by NSP. Typically I got the feeling that most were trying to sell me whatever they had in the shop rather than what my son needed. What can you all recommend?