Well, Superman doesn't exactly need tech in his costume. It makes sense for folks like Batman or Green Arrow to update their equipment from time to time, since their abilities are tech-based. Superman's powers are innate, so having a high-tech-looking suit doesn't really do anything for him.
If you have to change the look of the costume at all, I'd go with Superboy's outfit from Titans tomorrow, where they got rid of the trunks and put the red in his belt instead:
