Pump recommendation since my gpu/m.2 ssd pump blew up. Single or keep it dual?

[scgt1]

I had dual ddc 3.2 18W pumps with XSPC res tops configured as follows:

Loop 1
cpu-->Maximus VIII Formula board block-->UT60 360mm--> back to res top

Loop 2
GTX 1080 FTW-->Kryo m.2 ssd block-->external RX480-->back to res top

I didn't have heatsinks or changed bases on the pumps because they just weren't available back when I got these pumps. They have gone through you can say 4 builds now. Always being setup as cpu to mobo to internal rad and gpu to external rad. I just recently got the Kryo m.2 for my 950 Pro so that is really the only addition other then cpu and mobo changing but still using the previous gen Formula board blocks.

The options I guess here are:

1. Replace both pumps with the same. (They have been going for 5.5 or so years now but only for gaming then the computer is turned off since they are in a game rig. This is 2-3 days a week for 2-3 hours a week in the evening) Obviously get heatsinks of the different metal bases for them since they are bolted directly to the bottom of my 540 air in the PSU compartment in front of the psu.
2.Upgrade to the 35x individual pumps setup as separate loops or link the pumps together to make a single redundant loop
3.Upgrade to the 35x dual pump setup which would be a single loop although are different tops made for this pump setup? If not I don't think I have the clearance for it since the out is on the front.
4.Go with a single D5 variant making it a single loop.
There are so many options for the D5 pumps with tops, brackets, upgrades, kits, housings it's insane and I don't know where to start lol. Also how would 1 of these compare in size to the current setup of ddc 3.2 pumps next to each other with XSPC res tops? I may not even have the space with mounting it vertical and a res installed on top of it. I know they are larger then the ddc pumps but are they considerably larger?
The space I have to work with is below

[Baenwort]

If you haven't already done something I'd say go with option 1 to minimize the time you put into it. You won't get a significant boost going to a single D5 and top and a pair of new pumps would be a drop in replacement for a system you're already happy with in it's old configuration.

Also, if you're old DDC's are old enough you can get a PWM controlled version this time.