Get a neutral set back seat post but NOT a forward seat post, at least in IMO. Don't go beyond 75/76 effective seat angle or you'll throw the handling way off. Add aero bars and you're set to go.

There is another possibility called the "big slam" position. Different approach - seat back, lowered a bit an shorty aero bars. Read this article carefully.

http://www.bicyclesports.com/Slam_Setup.html

You don't need to sit at steep angles if you dont want to. All of the worlds fastest time trialers all have their saddles in a slack position, in relation to the bottom bracket.

If sitting rearward, I suggest getting an adjustable short 80mm stem, such as the Ritchey Pro.