If the download link is broken, then send a Personal Message (PM) to the original developer.
Otherwise, as Khris suggested, the other heavywieght engine made with AGS is by DoorKnobHandle (DHK) and can be found here (small "download sources" link) : http://www.adventuregamestudio.co.uk/forums/index.php?topic=49687.0
I don't know the pros and cons of each of these engines so you should really try to get your hands on both of them and try them out to see if they're easy to adapt to your purposes.
Otherwise, as Khris suggested, the other heavywieght engine made with AGS is by DoorKnobHandle (DHK) and can be found here (small "download sources" link) : http://www.adventuregamestudio.co.uk/forums/index.php?topic=49687.0
I don't know the pros and cons of each of these engines so you should really try to get your hands on both of them and try them out to see if they're easy to adapt to your purposes.