I long planned to shove some GBASP guts into a GB shell, but I never got around to it.
I'm also all on board for these backlight mods. I'd been meaning to get an AGS-101 model SP for some time and switch the screen out with that of my NES Edition SP (which apparently wouldn't work, so I'd probably have to switch the whole casing out)... but with a backlight mod, I'd probably start using my original "arctic white" GBA again!