The noise problem is pretty easy to deal with, and relatively inexpensive. If you're interested, let me know and I can help you. Basically the bulkhead behind the seats is the major source of noise, and there are vibration absorbent mats that fix the problem. Several different companies make the material, start your search by googling dynamat and damplifier. You will find a bunch of references for different materials.
Regards,
Mike Dolan