Yeah we are going to need to know a lot more about what you want as a whole (complete list of stuff if you have it)
So basically you want to avoid something like I did (below) where I had to snip the ram heat spreaders to get it all to fit
inside the case right?
That might be a problem with two of those cards. Using a radiator ready box, right off I can think of something like locating both of them up top. However the length of hose may not allow this (and as above you may get ram clearance issues). Another way would be to mount the lower card to go out the back of the box and the upper car to use half the top. This would still let you use at least a 120mm~140mm liquid cooling solution for the cpu if an air cooler would interfere with the hoses. But again, you may get ram clearance issues. There are a lot of cases that will allow you to mount fans/radiators practically anywhere you want, but sometimes at the cost of generating case heat. The fan/radiator assembly may need to pull into the case and effectively undermine the point of most liquid cooling solutions.
Replace my CPU cooler with two of those, but side to side for an idea