I have a 2nd story concrete deck made with Polydeck... new construction home... and wish to put up railing... Would like to use aluminum balusters that look like wrought iron, probably "Deckorator" line... and Trex post and rail supports... But what would be the best method to attach the Trex posts to the concrete deck?

You can buy galvanized 4x4 boxes in the same area as the Trex posts. The boxes are masonary screwed to the concrete then the post fits inside the box. You can add trim at the base to hide the edges of the box.