Secret Jardin makes a 10'x20'. You can also daisy chain them together and remove the partition walls to make as large of a tent you would want.
https://www.bwgs.com/details.aspx?sku=INT215&AC=1
Good luck.
Actually phat filter has never changed their name. They claim phresh just used the "ph" to ride their coat tails. Here is a link from their blog.
http://www.phatfilter.com/hydro/page/2