>>1442169It seems kind of pointless. Modern enduro bikes are at the point where they are more than capable at downhill riding. Adding an extra 20-40mm of suspension isn't going to do much. If anything it is going to make the hike worse by changing the geometry.
I would just get a longer trail enduro bike with a coil shock and swap out the air spring in the fork for a coil spring or one of those dual chamber air springs. Something like a specialised enduro, you should be able to pick one up since they updated the design. Or if you have the cash grab the knew one, its more or less a downhill bike.