You'll go broke buying burbee seed packs with any larger size garden. You should have a seed company near you somewhere to buy in bulk.
I've used Saunders Seed co. In tipp city Ohio for years. That's where the farmers get there's too. They've been in same location since 1800's. Might be able to ship to you and they have everything. I even order sweet potato plants from them, but pick up at there location. You might give them a call if you can't find a local bulk supplier