If its this guy he has both listed on CL. This is about the best deal I've seen lately.
Pin vs Ball...well ball lock are narrower and have a manual relief valve with an air line style coupler, pin lock are shorter and fatter, have a twist lock coupler and a burst valve. So based on those items and my space i went ball locks. I like the manual relief valve and my kegerator is an old upright hotpoint fridge so space is a premium. Tall narrow kegs with a coupler that can be at any angle worked better for me. I can fit 4 ball locks plus the CO2 bottle. YMMV. Happy brewing.