Buying first cowboyboots without trying them

Title. So my foot is lenght is 25cm/9.84inch and width is 11cm/4.33inch. Charts says that with my foot lenght i should wear us7.5 or 8 but all my shoes are size 10 becuese my feet are so wide. There usually almost inch between my toe and end of shoe. When ordering boots should buy similiar size as my sneaker becuese if i buy size 8 it would not probably be wide enough even if it is eee. Not even sure even 10eee wild be wide enough. (Sorry for bad english)