my son was 11 at the beginning of last season and i ended up getting him dynastar serial troubles, twin tip 80 underfoot (now "6th sense" i think)and have been very happy with the choice. you may want to go a bit wider out there but a solid twin will give him a good tool for the park as well as let him rip up the rest of the mountain. while he's not a real super park rat he spends alot of time there with his buddies - where da boys want to be!!! he's pretty tall and i went long with 154's and theyre short now after 2 seasons while not a junior ski per se i think most twins are marketed to that age and ski a little softer.