[Question] I have an evolution question for you guys

I am about to hit level 24. I have two pokemon that are going to be ready to evolve very soon that have multiple options for evolution. One is Gloom the other is Poliwhirl. I have the special item needed for the evolution on both. What is the better evolution in general for both of them (Vileplume vs Belossom and Poliwrath vs the other one). I will eventually try to evolve both but combat wise, which generally is the better evolution of the two?

please pardon spelling, the second gen pokemon are still new to me