I'd surprised if ebay/amazon doesn't have everything in the one place, the tubing and odds and ends for 5mm are dirt cheap.
You can buy 2 different types of tubing soft and hard, I remember reading that you shouldn't use the soft stuff, personally I find it works the same only it's more user friendly, it's pliable as opposed to the hard springy.
Fwiw the hard stuff pushes snugly into the soft tubing and forms a water tight seal.
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It's handy if you're feeding different sizes.
The important part is the pump, manifold and tubing once you have that the ends can be terminated to suit with tees, crosses or taps the flexibility has no limits.
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