How are you going to attach that block to a CPU lol?
Why try and reinvent the wheel? We used card radiators and Aquarium pumps in the early 2000s, We moved away from that junk for a reason. Take the advice of those before you, dont try to cheap out and by out of spec junk to save a few bucks and have to deal with issues and trial and error we did.
Companies have came about, WCers have found what works and what doesn't, we already did all the leg work with the junk, buy whats easy and available. If I were you, just buy an AIO, that 25 dollar pump, that you didnt link but I am sure you are going to buy. Ya it looks like a D5, it will also not pump the way it says it will, and it will be dead in 3 months. I got my brother in law in WCing and he bought 5 of those things in a year, and finally bought a D5.
Your not saving money doing this, blocks are not expensive because its for WCing, they are expensive because its expensive to make not junk. D5s are not "official" WC pumps, they are rebranded Laing D5s, and they cost more than what they do from WCing companies then non WC companies, or at least the same amount. They are not expensive because they are WC, they are expensive because they are Good Pumps.
Same with radiators, good quality alu rads, cost as much as copper WCing rads, and Alu is alot cheaper, its also not nearly as good as copper.
If you want to cut costs, and dont care about using Alu, get a fluid gaming kit, 140 dollars full custom loop. Your project will cost you the same if not more, as initial cost. And then cost you 10x more when everything keeps breaking.
Also it isnt going to cool anything to anywhere near 5ghz, that block has no channels, thats a box for water to run through lol. It isnt going to cool anything, aside from the fact it cant be mounted on a CPU.
Unless you meant to link this one, https://www.ebay.com/itm/Cooling-Wat....c100005.m1851
Which even still. How you going to mount it? You realize they are oxidizing the cold plate? That thing is going to fry any CPU you put it on. that is a Wish.com special man.
IMO, its not worth the cost of a decent rig to gamble on Chinese junk. Which is what everything your trying to buy is. If you really think a 4 dollar ebay waterblock is going to cool anything, you need to stop now. Before you break your rig.