I am aware that I should mail in my Fedral return with a Form W7 (to get my spouses ITIN) to Austin, Texas. What do I do about the State return. When do I file it? After getting the ITIN ? Should I file an extension with the Stae of PA as it would be after April 15th when I get my ITIN.

Thanks in advance.

Yes, file state return after you get ITIN. File the extension.