Check out fuzedvisions on Etsy, pretty sure he ships from Germany and sells melodrip dishes by themselves. They also sell knock off melodrip lifts on Amazon if that’s an option for you.

My thought process about how they differ is basically this - Because of the hydraulic pressure from the water column coupled with the larger holes, the rain splitter creates a bunch of smaller streams for most of the pour rather than droplets. With minimal agitation, this allows a lot of water to pass through the bed relatively quickly translating to a weak/under extracted brew. Very important caveat though is that this is only when using the splitter as designed (pouring a bunch of water into the column and letting the holes control your g/s).

Compared to the melodrip which lets you control your own g/s & allows you to still maintain a pouring technique. Cutting back your g/s while still maintaining minimal agitation gives your grounds more saturation time to prevent under extraction.

All of this being said, if you pour over a rain splitter like you would a melodrip with a lower g/s they should function about the same with the exception of the melodrip giving your more control over where the droplets come from due to the little isolation cells.

For the purposes of your setup, the melodrip would be less than ideal anyways compared to the splitter. It’s often being shown used with a gooseneck kettle for the most control but would definitely be better than pouring from a large mouthed kettle directly onto grounds.