What armor for a tanky scrapper build?
If you can live without the HP, the universal power tank setup for pretty much all classes is zerker weapons, knight armor and cavalier trinkets.
You never did specify if this was WvW/PvE or sPvP.
I personally play my HoT Metas with a Soliders Hammer Scrapper.
Along with Sigill of Draining (Life Steal on interrupt), Sigill of Bloodlust and Rune of the Scrapper.
The Vita+Toughness yields very nice sustain against the Jungles hard hitting enemies which can be further increased with Heal and Bulwark Gyro as well as their Respecive Toolbelts.
Also this enhances the impact of both Perfectly Weighted and Mass Momentum Traits as well as usual Utility (wrench) food.
If you go absolute Ham on it (Soliders full asc, full might, full sigill, pow. + vit. Food and Utility) your hammer will hit like a truck (4000+ Power) while still being on a high sustain.