This thread probably should be in the Streaming Media Players and Standalone Players/Recorders forum which is where the Liteon LVW- series discussions are.
That said, I don't have experience with any current drives in these units, but I'd suggest you try any Liteon drive you can find which has a MediaTek chipset (not NEC). You'd have to look at this discussions in this forum to verify that. Also remember that you need an IDE (PATA) drive -- SATA will not work.
If you've got any DVD writer drives at all around, you can just try them out and see how they work. You shouldn't even need to mount them inside - for testing, just take the cover off and plop the drive on top of the existing one and plug it in. Do disconnect the power before you do this - the power supply is live all the time in these units. And good luck.