If your even remotely thinking about selling the car I would do the Ebay job or a JWS 99/00 STi engine on the cheap.
Straight bolt in job with more power, better heads and all. Then Verso. Keep and play for a while then sell.

If your keeping the car, like I did on MY99 WRX either:
Cheap Way: JWS or used MY02+ STi EJ207 long motor with AVCS disabled. JDM engine better. Verso.

Proper Way: Built EJ207 short motor, JDM V8 STi heads (ported + extras). AVCS wires connected. Worked VF34/35 then Link G3/Autronic/Motec.
You really need to upgrade the gearbox then to at least a MY02+ WRX with the 4.444 rear diff. RA box better if still keeping the 5 spd to keep costs reasonable.

If you're spending the money on an EJ207 bottom end, you really want to do it justice and get value out of the expense by putting proper heads on the thing.

J