Jay if you have an air gap, at least 1" from heat source for your AC lines. Any aluminized sleeving will work. Ours is called Thermaflect Sleeve, but any one like that will work just fine.
If you are generating that kind of heat, you may also think about adding some extractors/louvers to your hood. Good air flow is a huge part of thermal dynamics. In addition to the cooling benefits it can add a little downforce if you are racing/autocrossing your car.
Thos old tiger Racing hood back when Paul was still around were pretty awesome for both. He helped us test products.
I already have vents for my stock hood, as much as I love the new TF hoods I prefer the clean stock look for my Cobra. I have not seen any prices listed on your website but as soon as I get together a list of what products I will use I will be asking for a quote. I will be insulating all my HE coolant lines, AC lines and my exhaust/X-pipe.
Update #3
Yesterday was ~100F heat index so I did some measurements on the way to the gym. Fresh out of the garage and fully warmed up I had a low reading 38F coming out of my AC vents on the highway (MAX AC, level 1 fan). After just over an hour in the sun and a good heat soak my charge temp was reading 112F on the highway and my AC vents had a low reading of 53F (MAX AC, level 1 fan). This was only a 30 minute trip, I am sure that with more highway cruising it would have dropped some more but overall I am satisfied with the AC performance with the HE off-line and my trans tunnel/floor pan insulated with the foam/foil duct insulation.
Next step will be to install a bypass valve for my HE and insulate all the lines/exhaust but as it sits right now my Cobra is now comfortable with the AC running and the windows up.