When will Avast have its own security packet (incl. firewall)? Will it ever come or not?
You only need to browse or use the forum search function to see that an avast firewall is in development but there is no specified date for release.
When it is ready it is likely to be released as a suite in combination with the antivirus first not as a stand alone firewall.
Yes, it will come 
But as DavidR said, there is no specified date for release, but be sure you will hear it first here in the forum!