there are several threads on upgrading the ICE for the Evora in here. Google searching with site:lotustalk.com yields better results. Understanding the OP isn't necessarily interested in these sorts of details at this point since he will be purchasing years down the road (maybe) but since this thread is already helpful for others..
the Evora presents a pretty good soundstage and imaging options as it is. The front stage benefits greatly from just improving the drivers and adding power. Deadening the doors with about 2-3 pounds of high end deadener (raammat, hush mat, etc) and then adding in a few square feet of a light weight foam isolator/insulator like ensolite GREATLY improve the tonal range and output of the midbass drivers in the doors.
The factory sub location is subpar at best, provides very limited options, and the factory sub enclosure, power, and driver are crap. You can improve the driver and the enclosure by replacing both in the factory location, or you can expand the factory location a bit into that "cubby" with a discrete fiberglass enclosure, or you can build a pass footwell enclosure for a small driver. All greatly improve the system. Luckily in a small cabin you don't need crazy amounts of output to get clear volume.