Skunk2 have just released a scratch made intake manifold. I don't think anyone has even installed one of those on a miata yet, there's nothing documented as of yet anyway....

Should show some promise, it does away with all the restrictive stuff and puts a big (albeit) single throttle body in front of a new manifold with indivdual runners.

Personally if it were me, I'd try the Hydra. I'm currently using an MSII system and I'd rate it 5/10, it doesn't like cold starts, idling or figuring out what to do with the electrical loads. Could just be my system needing tweaks or a new alternator.

I'm currently most of the way through with what I want to do to the engine, most of it has been systematic and trial and error though, I haven't had a list laid out from the start, the list has changed as I've changed a few things and then driven the car to see how it feels. I'm building up an earlier model 1.6 though, so the engines will want to behave differently anyway