Best server hosting option?

So, I'm looking at Citadel Servers, and Bisect Hosting, and I'm curious which is better and what option to choose. Can't host ourselves due to bad ISPs

No mods. There's really only 2 of us that play heavily, but could have 4 players on the world sometimes. Probably would be a large sized world.

Would a cheaper option like 2-3 GB of RAM from Bisect run well? Or should I go with a higher RAM option?? Or even Citadel where it defaults to 6 GB of RAM??!