There is not really too many easily acquired (there is some I'm sure if you feel like digging) commercially available designs in PSD format worth getting that are publicly offered for free (paying for a membership to a place that gives you free slices is not free) unless you make them yourself, and at that your time isn't free so...you either should consider paying a little upfront for legit commercial use and have a selection to pick from at a site with a wide variety or go hard and learn photoshop.
Option 2 (opinion here) will always be better unless you have the money and can convey exactly what you want to your designer and this based on paying for something and getting it once is final, paying with time to learn to do it yourself provides reproducible results.
Again I am sure they are out there...but not many people that are aware of quality free to use commercial skins are going to be quick to share them so others can make money off the same skeleton as them making their "design" worn and to played out.