Pictured is the deck rehab I completed last summer, removing the original decking (Mahogany) and railing (PVC wrapped Pressure Treated rail/baluster), and laying Trex Transcend with a cable railing system. The original deck had been spec'd for 12" OC joists, so I did need to add any of those, however, I used a picture frame layout on top, and addiitional framing was required to support the deck boards that ran parallel to the joists as part of the "picture frame" layout.
The original stairs were replaced entirely by new ones I cut to provide a reduced slope and wider tread; a pair of 12v DC LEDs is used in each riser for lighting.
I used the Trex Hidden fastener system for laying the Transcend planks, and where those weren't appropriate, Cortex screws with matching color plugs. The railing system was ordered over the Internet from Nexan Building Products and went together without problems.
The biggest challenges for my one man operation was demolition -- dirty, messy and lots of material to move and store, and in the final stages, hanging the 1x12x12' Trex fascia, which are fairly heavy. It took all my ingenuity and experience with jigs and clamps to get these into place before I could screw in the Cortex fasteners.
Costs: About $4800 for the Trex, $4200 for the railing, and ~$350 for fasteners, lighting, and misc. lumber.