Depends, really. But here are some tidbits that might help with your consideration:
- You can purchase whatever available options as long as they have an MX holes.
- Most of the puddings are OEM from my short research. As long as the keycaps face look "familiar" to what you currently have, you can safely assume that it's either OEM or Cherry profile. The main difference AFAIK is that OEM is slightly taller than Cherry.
- For ANSI, most of them available options are ANSI so this shouldn't be a problem. ISO sets are pretty rare on premade keycaps set and they usually tells you whether they support ISO or not.
- Bottom row might be an issue as there are some different size combinations, but as your keyboard uses vanilla TKL configuration; the usual stuff should be fine (all keys on 1.25u except for spacebar, which uses 6.25u).
- As for the key counts, getting more keys than what you useis probably a thing that you have to live with. Premade sets tend to give you more to lower the cost on their end. You definitely can get a set that matches exactly with what you have, but these are few and far between.
- Custom bottom row keys on pudding might be hard to find, whether its included on your set or otherwise. I haven't done more research on this too.
That said, I think HyperX have a pudding set that might fulfill most of what you want.