Every standard 2/0 lug I have come across has fit my 2/0 Royal Excelene welding cable. I did try some of the ultraflex stuff from from welding supply, I did have to trim that to fit in a standard 2/0 lug. I have some coming from Del city that were the cheapest I have found online, hopefully those fit and crimp nicely.
Windy Nation 2/0 lugs on ebay fit well, as well as 2/0 lugs from genuinedealz on eBay. But welding 2/0 fits perfectly in all my toolmaker 1/0 amp inputs and any other car audio 1/0 designated inputs.