One of the suggestions would be to team up employees based on projects. This approach helps in recognizing achievements accurately and encourages employees across the entire company. In simple terms, it's like appreciating the top student from Accounts compared to the entire college. The college recognizes students from Accounts, Biology, Management, Arts, and appreciates them individually and collectively. This makes them competitive and productive both in their fields and against the whole. This way, everyone is satisfied and recognized, making the work easier for you too.
Do not worry about the budget. If that is a concern, you can reduce the prize amount by distributing it.
Instead of following existing models, for these kinds of situations, it is always feasible and more adaptive to bring in your own practices, which have more credit and uniqueness. This approach allows you to think easily and manage the environment in your own way, but in a worthy manner.
Nobody needs to worry about the kind of practices you adopt. As long as it is a win-win situation and a system, instead of scratching our heads searching for big and popular model adoptions and trying to make them fit the environment, in reality, it does not!
Think about that.
All the best.