I am doing a bungeecord server build! Check it out! I do a full tutorial, and more!
www.youtube.com/craftkingsly

Ill happily setup bungeecord for you

Yup, spigot is same as craftbukkit, instead its actually better cause its more customisable, and the way its coded, you will see up to 50% drop in CPU and RAM usage. Though the only minor downside is that it depends on Bukkit API, so it will only update after bukkit updates, which realistically is not even that long.

So basicly, download spigot version you want then, drag and drop it into your server files/folder. Restart server, so it generates files needed. Then download Bungeecoord, set up the Bungeecoord as shown in their tutorial. Go to config for bungeecoord, something like "config.yml" look for empty ports or make your own. So for example for your hub server you use 25959 port in config.yml for bungeecoord, you will use that same port in server.properties for the hub server. While this is just a quick summary, I suggest looking at in depth youtube tutorials.

Use Spigot + Bungeecord, but please look up tutorials on how to use it properly. If not it'll probably get griefed quickly.

Here's a tutorial from a quick google search, should be effective considering the source.

BungeeCord will connect servers together

I don't know much about packets and services, but in Minecraft, it sends you to a server at the click of a button, so there should be a way to replicate that with your own code.