Playing a map with Rebirth modpack

[Sjustus548]

I'm wanting to start a map for 2-4 people using the Rebirth modpack and a few other additional mods.  I'm not sure if I need to use a dedicated server or if they can just join my map?  If I go with a dedicated server how much memory should I get to run the server the best?  Also if you can recommend your go to company to host the server I would greatly appreciate it.

 

[Ganeshakw]

If you are going to record the gameplay, please share the video link here.