The FMU (we call it an AFPR) is a good setup for a car running up to 8 psi. It's also affordable. We've been selling a similar kit for the Miata since, geez, 92 or so. One of our customers has 215,000 miles on his car so we know it works well.
If we decide to offer a kit that goes beyond 8 psi, we'll have to go with some sort of piggyback computer (such as the Link we use on the 1999+ Miatas) with auxiliary injectors or some other sort of engine management system to run larger injectors.
What we do will depend on the strength of the engine and transmission. It's too early to say right now and it's a matter of discussion around here.
Keith