Although C-West RX7 looks wild, best part of C-West is the combination of visual impact and race developed aerodynamics.
The body kit is used for Japan's Super Taikyu (endurance) racers.
As for a detailed Aoshima RX-7, the best way is probably to install the engine from Tamiya on the Aoshima kit.
Just cut the oil pan from both kits, and install the Tamiya's engine assembly. The engine room of the Tamiya kit isn't so detailed, so it doesn't have advantage of swapping the entire chassis, considering the workload of adjusting the tire and wheel arch clearance etc.