The boxes I use are called 4" metric. A local Northern California bussiness "Reynolds Packaging" will deliver locally if you order a pallet. 250 boxes for about $1.20 each.
Heirlooms do much better placed single layer, just touching(no rock and roll) and stem down. You can stack these boxes up to 10 high without smashing and they display fairly nice on a table.
Here is a picture to get an idea.
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