Measure twice, cut once! Unistrut also has the advantage of being reconfigurable as opposed to a welded sculpture. I can't think of any particular suggestions for building with unistrut other than the strut is relatively cheap but the strut-specific hardware is expensive. Anyway been brewing for ~4 years on a 3-tier strut stand. The stand is built like bookshelves - the tiers extend across the brewing structure. The bookshelf design has the advantage of ease of making and reconfiguration, but the tiers make access to the tuns more limited.