I like 6"x 6" column installation for multi story or large volume custom area decks. If a one story deck is planned, 4"x 4"posts cross braced with staggered mid span joist blocking is aok . The ledger attached to a house and column footings are vital. Stand alone decks are good choices for a low height deck such as Plt's project. Paving stones or patterned cement is a great idea for an on grade patio project. Plt's wife would then be attracted to an accessory foliage garden to match the effect. It keeps him working longer too.