Eidan,
I know that you said you dont like icons cluttering your tray, but AVAST is the one icon you should leave.
If you want to remove the "i" icon, then right click on it, and select the "merge with main Avast".
The "a" icon assures you that Avast is functioning, and when it is checking files and emails. This is one of Avast's features that make the program so great.
But if you want them removed, then raman's instructions will do the trick.
Good Luck