most people are running the ER chargepipe which comes in different configurations for everyone's needs including different blow off valve options or none so you can run stock diverter valves and in polished or in a black anodized finish for a more stealth OEM look.
you will see no gains with a chargepipe but some say throttle response is a little better with one and you won't have to worry about leaking boost with stock or higher boost levels.
http://www.evolutionracewerks.com/?q=node/53