If humankind ever reaches the 'giant floaty-brain guy' stage, it will probably stop there - Ultimate Man most likely croaked because he evolved himself beyond what was already the ultimate stage.
In the short story he turns to protoplasm, which makes more sense.
So if you plan on doing this again, are you going to try modeling your comics after ones from different styles and periods? What about something from the Golden Age - Jack Cole's Plastic Man, for instance, or the original appearance of the Injustice Society?
I seriously doubt it. If I ever did it again it would have to be with some sort of comic that I feel an emotional attachment to, and probably some desire to "fix," which points to GI Joe or some other 80s Marvel Comic.
It would actually be more difficult to not match their style.
Although I love Jack Cole, I am not at all sure what I'd learn from studying him. Plastic Man is the perfect expression of the super-heroic principle of "Figure out what you can't draw and then make it their super-power." Plastic Man is all about terrible,terrible anatomy.