I don't see anything awkward about the English - material need is a real thing, contrasted with, say, spiritual need, or material desire. However, I don't think it would be a correct translation of the French sentence given, where "matériel" is clearly a noun.
"Matériel" can also be an adjective, so it's possible the French version of your sentence would be ""Ils ont tant besoin matériel," although, looking at it, I tend to want to put a "de" between "tant" and "besoin". I am by no means fluent in French, though, and I don't even know if "besoin matériel" is a thing in French at all.
We will have to await correction/confirmation from one of our resident Francophones.
"They so need equipment," is grammatically ugly. It's something a Cali-surfer or skater says (in slang). "They need equipment," seems appropriate. "They need THE equipment so much," seems a little better as an English sentence, but "so much" is very awkward in this phrase. "They really need equipment," is a much better English sentence than anything else.