Does anyone know where on can buy short gi pants at? where the bottom is at the mid calf.
As others have suggested, take them to a tailor. Here in my area, most dry cleaners can do the work or farm it out for you, you don't have to locate an actual tailor.
I like my gi pants short because I do not enjoy the feeling of having a toe trapped in the inside seam by accident, and because the kids I help teach have to be able to see my feet when I show them which way their feet should be pointing for different stances.
In any case, I wear a size 7 gi. Those are made for guys as big around as I am, but about 10 feet tall, so I have to have about 12 inches removed from the pants anyway. I have never been able to wear a gi as it came in the package.