yes go with exturing the circle down the curve, then take a look at some of the preset textures in Maya some of these may suit your needs you could even go about and add a layered texture node which you can then plug multiple textures in to get a layered effect on your pipe, so for example you could add a noise texture for a general colour, then go and add a corrorsion texture for a rust effect, then plug these both into the layered texture and plug that into your material, if you want lighting all the way down your pipe when animating, simply set up a lighting rig with is perented to the camera so for example you could have the light just sitting behind the camera pointing out and wherever the camera will go the light will follow