I have decided to include in my winter upgrades the addition of a washdown pump to hose off my front deck on my 60' Destination Yachts pontoon boat. I am thinking that when the boat is anchored with its nose on a beach, where it is 90 percent of the time I use it, clean water from the rear of the boat will be more useful than muddy water from nearer the front of the boat. But my understanding of fluid dynamics tells me that I will get better pressure and flow if I draw water form a pickup tube nearer the front of the boat. As a compromise, I have an open midship spot where my existing lakewater draw enters the boat. As you might imagine, I need some help here with a couple of questions:

First, does anyone have experience with the pros and cons of clean water traveling a long distance vs. close but less clean water?

Second, does anyone have thoughts on a good pump to buy? One thought would be to buy a 4 gph flow jet like the one that supplies my house water; that way I would always have the ability to rob the washdown pump if the more-important house pump went out in the middle of a trip. But I don't feel strongly enough about that long-shot possibility to use an inferior pump for washdown purposes.

Thoughts?