Tom, from what I have gleaned in your posts and e-mail, you are on the cusp of begining several projects, but some may not be ready to go, and perhaps this entity that wants you to do the one in PS is ready to start, and you are thinking of trying to keep your crews busy.
I look at the current diversity of design styles you are being engaged to work on and wonder if you will become, non-identifiable. You may believe that the mark of a great archie is to accept them all and show that you can design in all types of conditions. But, I am going to take the other side of that arguement.
I think you should evaluate the land offered in PS, and if you really feel in your gut that you can do a superior job with your own ideas of a design style that is different than your clients tastes and desired atmosphere, but something that says Tom Doak all over it, then tell them no, and move on if they won't acquiese. I don't think that water features per se are bad. It depends on how they are incorporated. But, a necessary irrigation resevoir of an understated design feature is better than an ostentatious waterfall in my opinion and I don't think that ought to be the determinant in your decision.
It sounds to me like you have a couple of potential projects that suit your ability more. I would do all that I can to make those projects happen, even if you still don't get the big payday that all archies who reach a certain level expect. I can't blame you for wanting to start making more money for your associates etc. But, I think that a couple of clinkers that could result from projects you are forced to step out of your design sensibilities on, and you will regress your reputation and in the end, your command of a big fee. I'd charge that big fee when you can say that the client can afford it, and you can say that you earned it by building a course worthy of what you can say is your best effort, not a compromise design.
To say this all bluntly, don't dilute your reputation with compromises you are not comfortable with.