The Dark Power Pro 13 1600W Titanium is about the only decent option there, but it's an expensive PSU, more than you need to spend, but also the only thing you've mentioned so far that is truly suited to the build.
As
@Dr. Dro Dro Says, 1000W is really close to the limit. I've not built 5090 workstations yet but I used 1200W PSUs with 3090/5950X builds a few years ago because I watched many different YouTube testers trip out their 1000W PSUs with such a configuration. I suspect a newer 1000W GPU with detuned OCP for transient spikes be okay - but like many of us are saying already, it might
work with 1000W, but it's not a good idea as a long-term solution and I'm not comfortable recommending it.
The Inter-Tech Sama is a straight up scam,
you are right to be wary. A half-decent 1200W 80 PLUS Gold is typically about €200 and if you want it to be 80 PLUS Platinum then €250 is the starting price. You don't need platinum, you need 1200+ Watts. Nothing truly made to 80 PLUS Platinum standards
ever comes with less than 5 years of warranty, usually 7 or 10 years.
Your system is going to draw about 800-900W, with occasional transient spikes well over 1000W. If you buy a 1200W PSU it will be enough for these components and no more. Personally, I like to build in some spare capacity for future upgrades, so a 1500W PSU is about what I would look at if I had your budget for a build. If you're trying to save money, don't do it on the PSU, it's one of the most important components.
IMO, the best way to do that is to shop around for a your 5090. There are vast differences in what people are charging for a 5090, easily +/-€500 because they're scalped to the moon and back and every 5090 I've seen on sale is at least ~€1000 more than it's supposed to be. If your budget is so tight you're trying to save €250 Euros on a PSU, then the 5090 is the wrong graphics card for you. Spend €2500 on a PC with a 5080, and hold that remaining €2500 in a savings account for a 6080 or 6080Super. The 5080 is going to play every game on the market to an incredible standard right now. By the time it starts to struggle, you have €2500 of spare funding to throw at something faster - probably faster than a 5090 by then, too!
