One of the problems we are probably facing is that you are in Europe and most of the posters here are in the U.S. or Canada, so the two lights listed are not ones that we see for sale here.
I currently have two 29 gallon tanks, one has a t5ho fixture with two 24 watt tubes. It is not a high priced fixture and does not have good reflectors, so the lighting is fine. I have been able to grow plants well, without an algae problem. The fixture is a Current USA Nova Extreme. It is a 30" fixture but takes the same bulbs as in a 24" fixture.
On the other tank, I have t5no's (branded as Aqueon, but the same as the older Coralife t5no's). I have two fixtures on that tank with two 14 watt bulbs in each for a total of 56 watts of t5no light. That tank is also doing well without an algae problem. Again, these lights have poor reflectors.
Reflectors make a huge difference in a fixture. If a fixture has a good quality reflector a lot more light reaches the tank.
You can always buy the fixture you want and if you find the light too high you can reduce it by using a piece of window screen attached to the plastic protector over the light bulbs.
I don't know if this helps at all, but just my experience.