[1.7.10] Sending load of data on client connection.

So basically dedicated server loads whole game from very bulky config, puts that together into objects and loads textures (e.g 32x32 image for "warrior" class) then sends it to client that connects (once per session, on login).

Note: By "loads whole game" I only mean my stuff far-related to normal MC (so no block and stuff that has to be initialized on mod startup).

Till now I was doing it by simpy sending huge-ass packet cargo containing NBTTags and decoded it on client. Problem is that it may take some time (sometimes even few sec in which case it spams in terminal)

Question:

Is there a way to send data (that is not referenced to EntityPlayer) using packets? I mean before EntityPlayer constructing so basically somewhere near client-server handshake?

OR

Maybe it could be sent inside constructor (as if entityToBeConstructed == you), so in that case question - how would sending bunch of packets affect player constructing?

Problem is - I want Client to be able to use loaded data right after you log in, so it must be done loading before "player logged in".