I can't comment on the heavy duty hose as I have no idea what that means.
Normal PVC hoses work fine, but you want to discard the water for the first minute or so each time. Their durability is limited by the off-gassing of the softener (which also ends up in the stale water) and destruction by UV.
The rate of off-gassing should
correlate to the temperature of the hose: Molecules with more energy (heat) move faster. How long it lasts against UV depends on the UV-additives and sun exposure.
If your garden is going to last a bit longer, I would recommend to install PE (poly-ethylene) piping under ground to convenient locations and using short flexible hoses from there.
EDIT 1: There are flexible food grade silicon hoses … but they are very expensive.
EDIT 2: It appears that EDPM is also an intersting material. For example this one
. No idea about price.