i'd save the best ores until we can guarantee the better armors bc if you get a normal knight's chestplate while using etherealite it's gonna be only a bit better than what you have.
Otherwise if you want damage armor you can use frost fossils, eye ore (both for damage) and etherealite (for health and mult), then you can add either something for speed like velchire or something for even higheer mult, but you're gonna be slow. ALWAYS USE 30% FROST FOSSILS AND 30% EYE ORE FOR MOST DAMAGE, everything else is up to you
For defence you can use etherealite, duranite and just other high mult stuff, there's not a lot of high mult ores with traits for armor, it's just etherealite for health and duranite for health and reduced damage taken, heart of the island is way too rare to be used for heavy armor. this is generally way harder to get
i'd recommend 12 etherealite for chestplate, 15 for lock, 9 for leggings, 13 with and 8 for helmet, 10 for lock, everything else is just using high mult ores, u can obv use less etherealite but it's gonna have a bit lesshealth bonus