not sure if you've considered doing a full sti conversion, i would personally be buying a full car off kris (sku81) for around $16k
eg:

1 X 2007 JDM sti 2L complete drive train and some body panels full interior and parts(everything but the shell) $16200 inc GST delivered to Aus(Brisbane)

you'll be looking at around 7-8k just buiding the 207 with reco heads gaskets etc

just my 2c