SS will solve the rust issue, but we have 7 cheap
automotive struts on our boat operating various lids and hatches and have not seen a spot of rust on them in 18yrs. Granted, they are inside applications (but two are fridge and freezer
, so they see moisture). Replacement is always because they gradually lose their lift
force over 5-8 years or so. I have had many of those spring things and no way would I use them anymore - way too many cracked skulls from accidentally bumping them.
If they do rust in 3 years or so, just replace them. These things only cost $10 if you stay away from the marine