I ended up ordering the Amarine models similar to the ones you linked
@Julian ; They where only 10$ more for 2 of them and I have had not so great of luck with stuff sold by Chinese sellers on Amazon (I think / felt those other ones where Chinese junkers). Amarine was better known brand to me.
I'm pretty impressed with the weight and apparent quality. They look nice, feel super heavy and have no obvious flaws.
I mounted them on the exterior pipes of the Bimini cover on the sides nearly even with the Captain Chair. I wanted to put 4 across the back of the tower but the Bimini Cover material wraps that pipe completely and I wasn't sure I wanted to start cutting it apart or something just yet.
I wrapped the pipe with some of that drawer liner stuff for toolboxes -- and put I will be putting some threadlock on the screws soon as I figure out where I want them permanently.
I did only order the 2 -- I will get 2 more at least, more if I can figure out how to use the backside of the tower. That spot would be perfect for like 6-8 rods.
The 2 I mounted survived and stayed in place over a 2 hour cruise this weekend.
EDIT - The one thing I did notice -- The outside is clearly polished Stainless Steel; the inside however looks a little rough when I peel back the rubbery lining; based on how I see "other stainless steel" things on the boat "weather" saltwater exposure -- These might end up flaking apart in a few seasons. Ex - They look similar to the docking lights build material -- I've only had this boat about 2 months and those are already showing the salty metal flakey crud.