i'd repair what you've got if all was right with it before head gasket going, but do remember you'll need to remove timing belt and not unless its very new you might as well replace that as well so the expense does mount up if you'd like to go 2-0ltr route theres alot to swap i.e sump and oil pick up ,water pump and flywheel also theres the ecu and wiring to sort out to get it running spot on.