"Powerstroke2000".....I just took two Anacin to make my headache go away after reading your post :B
You have a lot of good questions, but way too many for one post. You never really define what you're looking for. Only after reading about some of the equipment you want could I tell that you had a DP in mind.
You need to narrow down your scope, which is pretty easy. First, give us a general budget, new or used and some length parameters, like 36' -40'. Once you do that, people can start making suggestions. If you tell us you have a $300K budget and want to go used, you might find a Newell that you talked about. If you tell us you have a $150K budget and want to go new, it's going to limit you to a very small market of DP's.
You'll find that once the budget and few other things are identified, you'll soon know what engines typically come in that range and what components, like Aqua Hot, are available at that price point.
