For the valves, springs, and retainers I have skunk2. Any high end after market valve train is going to make a huge difference. Go for double springs, and buying rocker arms is not necessary.
And as for pistons I would buy just whichever is cheapest.
Build thread:
http://civic-eg.com/viewtopic.php?t=21878
http://civic-eg.com/viewtopic.php?t=21878