If you're making a portable you probably need something to watch it on. (Unless you want to guess what's happening in the game, but I wouldn't advise that) Anyway, this forum is your "Hacking a pocket TV/screen" one-stop solution. Share your experiences and knowledge here.
If you are talking about LED modding, then no, it is personal preference. LED modding reduces the amps needed from batteries but also gives light and dark areas on the screen. Personally I prefer uniform light levels on the screen, although it means more amps drawn.