Kinsler- if you have he talent to set it up - is the goods.
more responsive, crisper, and capable of ridiculous power.
The other thing you need for a kinsler setup is the money- bring a lot. Plus it looks cooler.
An MEFI 4/5 is a really clean way to go as well.
An injected - 650 -700 is doable but expensive in a marin-ized setup. Much more expensive than in an auto setup.
Pay attention to idle quality and maintenance intervals.
Keep us updated on what you do!