I second the above comments about Scadden, I have a 10 Skykomish Sunrise and while it's good for lakes or Class I & II waters, it's not what Scadden claims. It IS good for fishing still or easy waters by yourself as I can load (on Yakima Rack on the top of my truck shell) and carry it by myself. For what you want, get a real boat. I think you need to decide on a raft vs a cataraft; raft will carry more people for the same length, but do you really want more than 2 and an oarsman? Things get crowded quickly and you'll not be all fishing while drifting. They each have their virtues. I have a RMR 14' Cat that IIRC I have just about $3K into the frame & tubes and used oars (Cataracts), but that's not counting trailer and accessories. You don't want to carry a raft that'll handle 3 persons on your rooftop or assemble it at the launch site, really. So now you need a trailer, seats, boxes, PFD's anchor(s) etc/etc. I have about $5K or pretty close to it in mine.
As said above, check out WashingtonFlyfishing Forums. Always one for sale there.