Well lets see.
It will pass emissions despite what SilviaGirl seems to think, perhaps she was thinking smog testing? Luckily we dont have that nor a visual inspection in WA. The SR just needs to be running right. The other options are to register the car outside of the outlined emissions zones. Another idea would be to find an S13 with the KA and pass the car on the KA then swap the engine out so you will not have to pass emissions again for another two years.
Who is your friend? Errin with the white S13 Silvia? GregariousGreg (from the board)?
As for shops, Garage SPL closed its doors last month so they are out. There is Stage in Kirkland right off 405 near costco. The guys at Stage are in the midst of an SR swap. There are a couple choices down south in Tacoma and Federal Way but I am not as familiar with those shops. Honostly if your getting an S13 and putting in a redtop you could do it yourself. Especially with the help of some of the people at NWN (
http://www.northwestnissans.com).
Since your local you can check out Foreign Engines Inc (1-800-333-9889) in Lynnwood (behind Acura of Lynnwood) if your looking for a deal on an SR that has a warranty, and lets you pick and choose parts for the swap. Last time I was there they had a brand new Koyo black copper radiator for sale with an SR. Just call them to see what they have since they get engines in weekly.
Im not sure if you went to any of the local Nissan meets but if you didnt you missed a chance to chat with the nissan folks, there were about 8 SR's at the meet that had 140+ cars. And there were 4 SR's at the meet that had about 15 cars, there was also an R33 GTR, LanEvo VIII, turbo upgraded A4 and some nice S14's. So there are SR's in the area if you need help or want to meet up.