Sorry, overlooked the diffusers on your site.
I would think a direct fit hood, but should come with a nice set of hold-downs, as these puppies tend to flap at speed.
I have no problem with ABS for the skirts, would paint them anyway.

One other thing I thought of : In addition to the 'stick-on' SS windshield surround pieces, how about a REPLACEMENT set. Many people tend to lose the OEM ones.