Altering the original sound signature is exactly what you wanted to do...
Main difference is that using a top class parametric equalizer, like DMG Equality you can surgically tweak the sound signature to your preference (like professionals do), without causing unwanted alterations to the sound. On the other hand, change the pads, and you'll get a different sound signature that will change everything at once in a way that you can't adjust to your preference.
I think you can demo Equality for free if you want to check this for yourself. Equality would cost you more than a pair of pads, but it's a very good investment in the long run.
http://www.dmgaudio.com/products_equality.php
You can always go the pad route latter, but it's by far a less precise method of tweaking the sound signature.
Most of the times pleather/leather pads will increase the bass so highs become softer in comparison but the same normally happens with the upper midrange.