Can I suggest ice hockey? I see there are a couple of rinks with learn to skate hockey programs near Seattle. I started my daughter in an excellent one at age four (across the country from you, sorry!) solely so she could learn to skate (we were not a hockey family -- I didn't even like the sport, but I hated my own tottering, terrified-of-falling childhood experience of beginning figure skating), and she took off in her second year and never looked back.
A good learn to skate hockey program will have the kids wear hockey equipment (you have to buy it, sorry, but you can get it second-hand), and start them skating back and forth across the ice. My daughter's rink supplies chairs they can push until they feel comfortable without one. Then they go on to the fun stuff.
They start by having them line up in six lines, then blow a whistle to signal the first kid to start down the ice. At the next whistle the next kid takes off. Partway down the ice -- at the blue lines and center line usually -- they have them add something to it: jumping, standing on one leg, throwing themselves down and scrambling up, etc. Generally the kids love the falling, since they don't get hurt in all that padding. Sometimes it's just to their knees, sometimes they're supposed to roll once or twice. They slide across, scramble up, then repeat at the next line. Or they'll have them try balancing on one leg, or going down to one knee, which they won't be able to manage till they've been skating for a while, but you can see they're picking up skills to make them comfortable on the ice, skills they would use playing hockey.
They'll set up obstacle courses and relay races, skating backwards and forwards. At some point (half way through the year?) sticks are introduced and they learn to push the puck. Then half ice scrimmages start, generally way too early in the morning, but "Hey," the kids tell their babysitters, their classmates, and strangers at restaurants, "I play hockey!"
One possible advantage for a shy child: the face mask and hockey uniform give them a certain anonymity -- it's hard to see faces, and impossible to see bodies. Being a little overweight can be an advantage. Also, at seven and eight it's expected that a parent will still be coming in the locker rooms to help them get dressed, or at least tie their skates, so you can still be there to support him. Another advantage is that it's the cheapest way to learn to ski I know of. I was told of this phenomenon by another parent, so I started my daughter skiing after a year of hockey, and the instructors couldn't believe she was only five. By her sixth time on the mountain they had her in level six (of nine).
YMMV, obviously. And hockey for the older kids has its risks, same as soccer, lacrosse, and football. But they go from not being able to skate to skating to playing hockey in three months, so I'm hoping it counts as a fast-feedback loop for you, but athleticism determines how well they actually play. The ones that take to hockey love it, even if they're not that good, and can't wait for the next season to start. Once the actual hockey scrimmages/games start, you'll know if he's one of these.