There really isn’t a remaster, just ports. There’s very little to improve.

I think there may have been some voice re-recordings here or there, but otherwise most versions are pretty much the same. I think the Xbox 360 Live Arcade version is missing some unimportant FMVs and some other minor details, it’s still completely decent.

It was a secret unlockable in the PSP game Castlevania: The Dracula X Chronicles with an added character and other stuff, but then you have to deal with the PSP emulation or whatever.

I’d suggest either emulating the original or getting it as a PSOne Classic on PlayStation Store unless some other route is more convenient.