I would love to see something like a FAL, basically a bigger deagle in rifle form. 20-round magazine, semi-automatic, three hit kill to the body and one-shot headshots.

Ehh maybe.
T rifle is hard to balance, becauae the core gameplay balance revolves around T having the superior, cheaper rifle.

At the beginning of every round CT has the advantage. If nothing happens and time runs out, they win. To counter this T have the AK.
An additional rifle would have to be as good as the AK, without being better. It would be tough.