As Jim said above, can you find a business that already buys and go thru them? I've said this before... I can't buy from certain sellers right now and I am a business. I just don't build 100's of cabinets every year. I think they are being careful because they are spinning out just supplying their big customers and there isn't any room for you.
Another thought: Are there cabinet CNC places that you could order thru? I guess it depends on how much you want to build when you say install cabinets, but maybe there is an RTA (Read To Assemble) place that will cut all your goods out for you and palletize. We have one called Lewis Cabinet that will CNC all the parts for Euro cabinets to any size you want. You can add a face frame and make it pretty nice. Or maybe just a good CNC vendor that already buys sheets and you could hit them up?