Help with First Vacation Rental Purchase please

[Bob Gillar]

I have wanted to purchase a beach home for quite a few years and I've gotten quite serious the past few months.  I've visited the areas where I'd like to purchase and am still searching though do have 2 current top contenders.  

While I can qualify for the mortgage needed for either home, the reality is that I need my costs offset by rental income. 

I have a large family and would like to use the home for a week or two as a way to gather the family and rent the remaining weeks. 

Are there any rule of thumb items (or I welcome more specific formulas/computations) that I should use in the process of screening and selecting a home?  I'm purchasing through an agent so I know they will have information from the previous owner's renting habits.  

As this vacation home will be out of state I will be paying a company to rent and maintain the home.  

This may be a personal choice but just thought I'd include this:  One house I'm considering is right on the beach but in a small town without a boardwalk or many shops or kids activities.  The other is 3 blocks away from the beach but in a larger (though still small) town with many family activities and shops.  They are larger homes (4&5 bedrooms).  The one on the beach is slightly cheaper.  In the experience of vacation property owners here, do one of these homes have more appeal than the other to renters or as an owner?

I didn't know how much or little to write so please ask questions and I'd be happy to answer.  

Thank you all in advance. 

Bob