quilt-serverside-mods VS krypton

not a jobs one, no. you can check out the serverside mod list here https://serverside.infra.link/

Have a look at this list. It's got a ton of useful server-side mods which you can use on your server.

To be honest, the natural path for those that come from Bukkit and derivates for the future is to either switch to datapacks, migrate altogether to Bedrock (that already have interesting advances on its addon/pack system) or switch to Fabric server-only mods - There is a lot of possibilities already and there is also Polymer project that aims to "convert" some classic mods to server-side-only, so at the end maybe OP should look at it all and forget the Sponge thing.

This seems like a decent shop mod, for a larger list of mods you can look here. Another shop mod I found was https://modrinth.com/mod/diamond-economy

Once you have your server OS installed, look through the performance section of Quilt Serverside Mods (even though it says Quilt all the mods are Fabric compatible). Also make sure to set sync-chunk-writes to false in your server.properties.

I have been using this list to find some optimization mods but some mods in the performance sections seems to break the game (eg - Very Many Players ).

Here’s a good resource for server-side mods, some of them are for quilt but quite a few are fabric mods (originally the list was only fabric mods, also quilt is a fork of fabric, so if you wanted to give it a go, it has most of the same benefits fabric does)

Starlight performs substantially better than phosphor and greatly speeds up terrain generation. Krypton for networking performance. C2ME or tic-tacs (both aim to do the same thing and are not mutually compatible) greatly improve world loading and terrain generation but are experimental and, in my experience, not compatible with a lot of other mods. Dimensional Threading puts each dimension on a separate thread, but also tends to not be very compatible with other mods. FerriteCore aims to reduce ram usage. This page has a whole list of mods.

Krypton ( astei/krypton )

I would recommend a fabric server running krypton, lithium, starlight, tic-tacs, hydrogen, and ferritecore. Those mods are geared towards optimizing chunk generation and loading while having 0 impact on vanilla game behavior (the last two are geared for reducing ram usage). Of all the performance mods I've messed around with, those are the ones that I would recommend most. You could also add carpet and set it up to add tps to the tab list if you want to easily see that number.