Here's a link to Produce Auctions in PA. 

Maybe call one or more of the managers and see if you could be hooked up with a grower or buyer who could work with you - someone to buy and arrange delivery.  I would suggest looking southeast part of the state for auctions - you will find pumpkin growers more likely in that part of the state:  Cumberland Valley, Kutztown, Oxford, Weaverland, Lebanon, Shippensburg, etc.