DownRiggin, I am sure you know John K and Mark Abetz, from running into them at Narrows Marina. They are friends of mine from our Gig Harbor PSA and would be sure to give you some heads up on this question. If you are like most of us normal fisherpeople, you probably don't have a ton of money (or maybe you do) to purchase one of those elite vessels some of the guys suggested. I too have had a notion to do what you want to also, but with my 21.5 campion there are limiting factors, mostly with the seating capacity and room for the clients to get around. The thing that I like about my boat is that I can economicaly afford to tow and run this vessel with a single engine and a kicker. It does fine with my 135 Merc. and 8 hp fourstroke Yamaha. The kicker is set up with a TR-1 auto-pilot that as a charter would be like having a deck-hand with you to keep the boat straight , when you were checking the riggers and landing fish.
I would recommend at least a 24 foot vessel and insure that it has enough deck space and seating capability to comfortably seat your clients. After all, most of your clients here in Puget Sound will not be the fishing elitist types and may not be able to stand the weather, and sometimes long lulls between fish. Not that YOU could have a lull between fish LOL.
Take care and hurry back.....the summer fish are on their way.

Steve Ng