Hi to all :)
Do you think the Orphek Atlantik v4 is a good lamp for the Peninsula 500? On my current reefer 170 i run a t5 /hqi hybrid. So I'm new to LEDs
Welcome to R2R. I really don't have much experience with either of your choices, and as a newbie I wish I had done more research on tank systems before I started my journey. That said, I would personally pick the Waterbox because you still get to pick your own equipment whereas the Red Sea systems look like they are more "packaged" with stuff that you may or may not like.
I recently sold my Waterbox so that I could replace it with a smaller frag system while living in an apartment. I liked the sump because it was made of glass, so I didn't worry about scratches when cleaning it. I also loved the glass overflow in the display tank because it allowed me to easily scrape it clean without fear of causing scratches. The height of the stand and display tank made it easier to view everything because I didn't need to bed over much.
I have seen much less negativity about Waterbox over the recent six months than I saw when I purchased my system new last year. Wait times were incredibly long, quality issues were abundant regarding damaged stands and display tanks, and it was difficult to get replacement parts. If I had a better experience when having my order fulfilled, then I would have been much happier. Even with the issues that I encountered and saw, I recommend a Waterbox based on my statements in the previous paragraph.