Your tank is of over 250L of water. In my opinion:
1. You have to use T5HO 54Wx6. I'd say that's the bare minimum. In terms of quality, Aqua Japan seems better as the reflector is of higher quality. But do note that the ballast of Aqua Japan is fixed and you cannot flip it over for daily maintenance.
Oh, haven't noticed that the aqua japan can't flip over. Do you know which shop is selling arcadia t8ho? I couldn't find them.
54Wx6 is bare minimum? Do you think I should make the tank to 16" high, so the light will be stronger? 2. For Teco products, let other c hings help. I cannot find any info about horsepower (HP). For your tank size, I'd say at least 1/10 HP is required.
Just read some post that teco always have water leaking. How do you think caompare to the china one? Which model is good for me from 海利 or 日新?3. He/ She must be kidding. For your tank size, none of them is enough. If space is not your concern, I'd suggest Eheim 2250x2. Otherwise, you may choose 2260.