I don’t think you’d have to bring the porch level with the front door sill. Pour a thin concrete pad (with appropriate framework / support / drainage) for the porch, and then build a step up to the level of the door. The step could be as large / extensive as you want it to be, and it could be wood, Trex, or concrete.
I don’t see how you’ll be able to have any sort of wood porch that close to grade.
Again, though, I’m not a contractor. I’m just spitballing.