When I bought mine, all internal plumbing came with it. You should contact Steve and see if that's still the case. Below is the description for the 150g on their web site and based upon that the plumbing should have been included.
This is a brand new SCA 150 gallon Starfire Aquariums with built-in overflow box.
Inside the overflow box, there are "three" holes are pre-drilled inside the overflow box. Each hole will be able to fit a 1" bulkhead.
Hard Plumbing Kit is included, SCH40 standard American size.
This aquarium is ready for Herbie style overflow.
Shipping is included for free via LTL trucking service for the 48 States only. If you can't offload the truck from the truck, you can request liftgate service for $40 extra. The driver will use the liftgate to bring the aquariums to the ground for you.
Please inspect the shipment before you sign off the "proof of delivery" as free and clear. Our shipping insurance will not be responsible for shipping damage if the "proof of delivery" is signed as clear.
If you want the tank ship to HI, New York City, PR, AK, GU, please contact us first for a shipping quote.
All SCA Aquariums come with 3 year manufacture warranty,