Thinking about it a bit more, most of the differences between rituals and infrastructure could be managed with small edits. There are four sticking points that come to mind, though.
First, enchanted items. They should probably just not exist for the infrastructure power. Could go either way on foci.
Second, time. Rituals can take a long time to prepare, but the actual casting always takes less than a day (barring weird corner cases). Spell control is often measured in exchanges, with the idea that you'll sometimes be casting while something is trying to kill you. You'll probably want to revise that for the infrastructure power; managing a project is much slower than casting a spell, but it's also much easier to multitask.
Third, human sacrifice. Ritualists can inflict consequences on other people to build complexity. Don't think that makes much sense for infrastructure, although I can think of ways to boost a project with your own consequences.
Fourth, backlash and fallout. Rituals explode when they fail, often with catastrophic results. Projects can go terribly wrong, but I don't think flubbing one management roll should cause a catastrophe the way it does with a ritual. Also, anywhere where a ritual would hit the caster with mental or physical stress a project should probably hit the manager with social stress.