As far as I have heard you can find them in China written in chinese,I am not aware of any direct translations of his work that have been published in english.There is a book by Wang Xuanjie called Dachengquan which is published in english and has some translations of WXZ work. If you haven't already I think you would also enjoy J Diepersloot WOS vol1.I would recommend contacting the Yao brothers and asking if they can send transcripts of his work,then you can get it translated over here.
I wish you luck,WXZ was without a doubt a true comtemporary MA practioner.
A Problem is only a Problem if you think it is a Problem and every Problem has a solution
Don't worry about losing lass,I've been wrestling wolves since you were suckling on your mama's titt
Groundskeeper Willy