If you already have the 8ight then i would say to just build that, It should handle better that the slayers and with a MMM combo on 5 or 6s it will be very fast. I would also say that it would be more durable than the e-revo, especially the drivetrain.
Toys:
Slash with VXL
E-revo with MMM/Teckno Nue 1515/1yf running 4s and 5s
IMO sounds like you are looking for a truggy for a cross between the ultimate durability of the 1/8 buggy and ground clearance of a MT.
But if you have the 8 already, I think you might be surprised at how well a buggy can do as an all purpose basher. Just dont try and take it on the rocks.
I can't decide if its more fun
to make it...
or break it...