Amy Mickey sells transfer paper and it is really high quality. You will need to google her, and it always arrives quickly.
Most craft stores sell printer transfer paper.
As to the resolution, my thinking is that because your are ordering it they are saying that the resolution quality is low.
I will talk to my husband tonight to have him help me look at the image, but I feel confident that the resolution is of fairly good quality because I choose large pixel counts for the images I use. I have also opened up the image in several different programs without distortion.
It will depend on if you are trying to stretch the image to much larger.
I really do think however, that the distortion message is coming from the company.
But, once again- I'll check the image and get back to you.