see heres the thing...
buy a head and do head swap but once you have VVL, you will want more VVL and because you have flat top DE pistons you are limited, so you then have to buy pistons for future upgrades and because the engine is all stripped you might as well refresh it with new bearings etc, then theres the whole external oil feed piss on and as ive already said, the VE block is better than the DE block...
what would you want from the engine dude?
I'd be quite happy with 190 - 200bhp from it.... Can't afford to be spending big money either ya know..