Seaching by H/L Ratio

Hi all,
I was looking to some pictures to use in Rev Slider on my website, about networking. I see many interesting images, but the ratios are different, sometimes.
I would know if there a filter to get the images of the same ratio.
Otherwise I would need to make some cropping or idea to allocate all that in a slider.

Sorry if the question is trivial. Rev Slider has many features, too many for a beginner, and probably I could make anything there, but anyway, I would limit any change to get a sense of recovering the pics for a fee, instead of making them.
Time is money, so if I give to someone would reduce mine.

Some general advice would be really appreciated on how to exploit the advantages of the photodune.