I'm specifically looking for an answer to whether a pressure fed or pump fed engine would be more feasible considering a mass of over 50T(metric, of course), and a single stage to descend and then re-fire the engines to ascend again.
I would argue a simple pressure-fed engine cycle is a good option.
These are low complexity and reliable, which are very attractive properties for a lunar landing system. They can not have high chamber pressure nor do they have particularly high thrust (50t on the moon does still not demand high thrust), but this these drawbacks are much less felt than in the first stages of orbital launch systems.
Restarting pressure-fed engines is also conceptually simpler since this is simply a question of vales, where restarting turbo pumps or for that matter any other pump system can be much trickier.
Much more than that can't be said without knowing the specific requirements.