I spent the last few days drawing a conceptual model in Google Sketchup. For the FIFA Women's Cup, it seems important to have an intimate stadium. The phase 2 study considered the idea of keeping the stadium intimate by using temporary endzone seats. However, another method is to shift the soccer field towards one end and have the sideline seats symmetrical around the soccer field and slightly asymmetrical around the football field (so at one end of the football field the seats are closer to the field, whereas at the soccer end the sideline border areas can meet the FIFA allowances).
The following configuration would seat 19,500 people in 24 lower rows and 24 upper rows; the breakdown would be 3,000 endzone seats, 11,000 seats along one sideline and 5,500 seats along the other sideline (however, the capacity could be decreased with a fewer number of rows). I imagine the lower bowl would be concrete and formed by local area tradesmen with all folding seats along the sidelines and perhaps one piece molded seats in the endzone (all folding seats are better for accessing seats though).
The ultimate capacity would be 40,000 - 45,000 depending on whether it was completely double-decked all around.