I'd consider the G2 version of the E-TEC, probably the 250 HO version for a little lower cost but still plenty of power.
Users are reporting that BRP is seriously sandbagging on the claimed fuel burn improvement! The advertized 15% reduction in fuel burn seems to be about right at WOT, but at cruise it seems to be more like 40%, which will put it well ahead of the 4-strokes! And while it's probably more expensive than the G1 models, it's really not that much heavier, when you consider that the weight numbers now include hydraulic power steering and a large oil tank.