the 2az sucks a LOT more than you give it credit for weasy
i wouldnt wish that pos on anyone. driving a scion was a huge letdown. a modern motor shouldnt fail up top as horribly as that thing does. its got 5sfe top end, and the 5sfe doesnt have any sort of variable timing.
i think the zz motors would be a great choice.. very light and have a reasonable amount of power.. or you can boost the hell out of them. still a light setup.