I had a HKS SRI in my car for about 3 years without a heat shield. During that time, i only tracked the car once and there were no problems that i could see/feel.
It was quite hard to notice any positive or negative gains in performance, but there was quite a note change when hitting vtec with it.

Imo go with whatever tickles your fancy. As you said, you dont intend to track your car, so i wouldn't worry about the heat soak issue.