Thanks a lot . I need to look for wrx struts..You might be able to use the struts, I don't know anyone who has tried, but I would not mix and match the springs.
Struts and springs work together for the proper movement of the suspension. Putting an undersprung spring (wrx) on a heavier strut (legacy) can cause undo wear/handling characteristics.
Since you already have the springs, just buy/find/trade someone for some WRX struts.