This post is probably too late, but get that new Black/Crimson DS Lite. It doesn't suffer from the glossy casing, so no fingerprints everywhere, like the other DS Lites/PSP. And it just feels nice.
i obviously picked the ds over the psp, lol.
for a lot of different reasons.
i think you might want a ds lite because it seems you really liked your ds.
plus, you can do everything on a ds lite that you can do on a psp on your ds with a flashcart
you should go to this website. it explains the advantages and disadvantages of a ds and psp, comparing them both