Your question is likely too general for a good answer.
What do you need specifically? What makes the solutions you’ve tried ‘meh’? What would make an office suite ‘better’?
There used to be a wine-based project specifically for Microsoft office. It was called crossover office. Not sure if it’s still maintained.
Good luck!
It’s where Linux really shines, to be honest. Those specs will be fine. Great learning opportunity for the students too.