Hi,
I did some reading and it looks very useful. Quick googling suggests there are multiple php language servers, including php-language-server on GitHub developed by Felix Becker. Would this be a good one to run or should i look at another language server for php?
I don't know any PHP since version 3 or 4 and so you don't want my advice on anything PHP related :).
I'd say either you just try the different language servers until you are happy and/or check the net what's used most by others.
Regards, Enrico