Sugimori's one fits much better than in-game sprites, although maybe in-game ones are smaller in size, but hey, this homebrew is good, taking up a few MB of space won't hurt.
However, if you decide to use in-game sprite, using GSC ones might prove to be beautiful, not color-wise, but they actually move, unlike DP/RSE which are actually two frames repeated
Although, color-wise, as this homebrew is made in 2008, maybe DP's will be more appropriate....
Oh, and maybe some sounds ripped form the anime wil prove very attractive I've been longing to hear "Pi~kachu!" rather than a horrible down-volumed-scream
Well, that's so many hopes from someone who can't help at all ^^ forgive me