Facebook lite down load from here:
http://pollux.androidapksfree.com/po...ndroid-2.3.apk
First make sure you know how to sideload apps. like this:
http://lifehacker.com/5943562/how-to...d-android-apps
The reason its not letting you do it on Google is because they want you to have the bloated one, facebook lite is developed for low spec devices that can't run the fat one, it's also good for low storage devices.
good luck.
I hadn't heard of mini for facebook, it's not made by Facebook (unlike facebook lite) and it apparently according to reviews, suffers from ads too, just be careful.