Ultimately, every individual's situation and goals are unique, and no web site will be able to provide you with the specific information you need to achieve success.The best thing to do is to consult with a firm or tax consultant who specialize in this area.  

Based on our "unique" situation (as everyone is unique).

I read on a different thread that someone used spiderman stamps and saw a good response rate so I definetly say use unique stamps! 

It is a very unique area.  

Each list will have a unique function and unique combination of fields (in addition to the normal ones like name, property address, contact info, etc).

I don't have anything to add but I did want to say, that house has very unique curb appeal. 

I think you are going to be surprised over the "unique" problems you run into that are going to run your expense up much higher. 

Esri defines 67 unique classes of US hoods with regards to A-D class. 

While in my opinion it's perfectly ethical (so long as you haven't signed an exclusive contract with any of them), it would seem you're wasting their time by having them all do pretty much the same thing.Of course, if more than one of them are bringing you pocket listings or providing some other unique service, that's a reason to keep more than one...but if they're just providing MLS data, I'd rather focus on building a strong relationship with the best one.

*Disclaimer that I do now work for a coaching company (though I bring a unique perspective having seen both sides of the coin)Best of luck with whatever you decide.