So yes thought I would post my build experience, hopefully it can help others putting theirs together.
Specs: (all purchased early 2020 hence the older specs)
ASUS ROG Strix X570-I
Ryzen 7 3700X
Cooler Master MasterLiquid ML120L V2 AIO
PowerColor Radeon 5700 XT Red Dragon
G.Skill Ripjaws V 16GB
2TB ADATA XPG SX8200 Pro M.2 NVMe
Corsair SF600 Gold
1 x Noctua A12x25-PWM 120mm Radiator Fan
1 x Noctua NF-A12x15 120mm PWM Case Fan
I decided to go for the Cooler Master ML120L instead of the Corsair H60 for its minimalist looks and the fact it didn't require a SATA power cable to reduce the cable mess. It fits just fine for anyone that's wondering.
As far as custom cables go, I got a set made through GEEEK store, very cheap at $20 USD and pretty quick with a 2 week turnaround. They also accept custom lengths so I had a go at measuring the lengths I wanted and adding 5cms on to the end to ensure they were long enough. In hindsight it was kinda unnecessary as they are slightly too long by about 5cm.
Seeing everyone's issues mounting the PSU in the regular way I decided to go with the reverse mount for extra space, these are the cable lengths I ordered.
PCI-E 20 cm
ATX24 32 cm
CPU 45 cm
However I think there was way too much slack so I would recommend for the reverse PSU mount (This is for routing the cables vertically between the motherboard/PSU)
PCI-E 10-15cm depending on your GPU
ATX24 27 cm
CPU 40 cm
Oh and I would also remind people to keep a close eye on your riser cable when inserting the core, I've been having a bit of trouble with it sticking out of the core, so its now looking a bit beat up despite my best efforts to hold it down when sliding it in... Actually check for any cables sticking out as I did manage to strip one of the cables on the Notcua fans (bit of electrical tape should keep it from shorting however).
I also had an annoying moment when I realized my PowerColor Red Dragon was too tall for the case at 132mm. There is around 15mm of clearance between the power connector and the bottom of the case so even with super flexible cables I cannot attach the bottom panel.
Since taking this pic I've managed to cable tie all the other cables so they do not poke outside of the core, but will need to find a low profile PCI-E adapter so I can attach the bottom panel in the future. If anyone has any recommendations on where to get one, let me know.