If that is what Freedom Tech Support said, you are well rid of them.
avast! isn't an internet/security security program, Windows doesn't recommend two firewalls and suggests you disable the XP one when you get a third party firewall; avast! doesn't recommend two resident AVs on your system (as do most other AV companies). This is correct because they are doing the same task and can cause conflict, but avast! isn't a firewall.
You do however, need outbound protection to stop any virus that may penetrate your defences phoning home with your personal details (accounts, usernames, passwords, etc.)
If Freedom is blocking ashMaiSv.exe and there is a way to allow access for this process in Freedom, then there would be no conflict, so you may be able to keep Freedom.
Zone Alarm free version as Bob said should fit the bill and has a relatively friendly User Interface for the novice firewall user.