Check out Soul The Salon in downtown Seattle in the Belltown area. I've been going there for 2 years now and the owner, Alex, has taken GREAT care of my hair. She does have experience with frontals and closures, because thats all i had been wearing up until last September, when I decided to take the plunge and go natural.
She charges about $70/an hour for a full weave, and requires a 20 minutes (free) consultation before an appointment is made. She does an AMAZING job! She's super nice & and really cares about the state of your hair. HTH!