Going to build a snorkel for my rig out of polished alumimum tubing.
I have found a supply offering straight,45',90'and 180 u bends in aluminum, they also sell silicone elbows in 45' and 90' along with straight couplers.

I guess my real question is what diameter should I go with?

They offer 2",2.5",2.75",3",3.5" and 4".

That aluminum will look pretty bling bling. Are you going to paint it or leave it shiny?

lol, that's true, big blingin'  some punks gonna want that shiny stuff you know...  go black!

Your right, too many little bastards with no respect roaming the streets! 

Remember back in the day, those guys would change there tune with a swift kick in the ass!!!
but now a days to many bleeding hearts and a broken justice system later and wa-lah too many punks with no idea about consequences!

Thanks guys (lol) now I might say screw it!!!   

thats the vibrant stuff. Works good welds ok