An alternative to warp sticks: flanged sticks!
This picture I stole from Tallbacka väv - because she sells them. (on her website, click on "Övriga vävprodukter..." She calls them bomhakar. And I am sure she will answer questions in English, if need be :-)
This kind of "stick" will never bend, whatever happens... and you only need one set. Per loom, that is. As they are made of steel, I guess that postage will be a problem for many parts of the world - .
When Laura visited some years ago, she managed to stow them in her luggage - see hers used here.
My table loom did not come with sticks, and I use it seldom enough not to want to buy any. I have tried both corrugated cardboard and bubble plastic, having seen both materials recommended. In my experience, neither works... the cardboard collapses and becomes flat, the bubble plastic is better, but only marginally. So I use a newspaper or two (no, not "paper from newspapers", but the whole thing). I put it in with the folded edge first.