I'm feeding all my nucs with pollen patties although we're getting a good pollen flow. I believe they survive the winter better with good fall feed. You need to make sure your mite counts are low too.You can buy a box of protein patties from Mann Lake, though I question why you would want to. Seems like there aught to be pollen coming in from the environment. I don't know if it is a good idea to do that now. You may not get the results that you are hoping for. It's not that instantaneous.
Any time now Keith Jarrett is probably going to chime in and say something to the effect that feeding protein supplement in the fall puts more nutrition in the worker bees bodies making them more healthy and disease resistant going into winter whereas natural pollen will be either stored away or fed to brood.I don't know if it is a good idea to do that now.