I wouldn't choose any of those air coolers and we refuse to install any CLC type AIO even when brought in pre-purchased.. Never seen a CLC ever that can compete with similarly priced air cooler in both thermal and noise performance. Just about every CLC uses mixed metals and with the aluminum rads, they require extreme speed fans to compete with the better air coolers.
Here we see (17:28) the Noc NH-D15 outperforming the H100i by 2C ... but it needs to be more than 11 times as loud to get that close.
Noc vs H1ooi
Here we see (23:15) the Noc NH-D15 outperforming the H100i by 3C ... and again it still needs to be more than 11 times as loud to get that close.
Noc vs H100i
Advance to 23:45 and you see the OLC type AIO w/ copper radiator on the Swiftch H240 AIO deliver
10C lower temps than the h100i and 5C lower than the Kraken at comparable noise levels.
Wanna see what 60 db+ sounds like ... it's leave the room loud.
H100i Sound test
Yes the Noc air cooler and the Cryorig are almost as pricey ($90ish here in US) as the the CLC type AIOs but you can get a Scythe Mugen Max here for $37 ... or a Scythe Fuma which match or outperform the Noc and Cryorig models.... f Here's the Mugen Max (black fan) and conversion kit for MA4
https://uk.pcpartpicker.com/product/8YrcCJ/scythe-cpu-cooler-scmgd1000
https://www.amazon.co.uk/Scythe-SCA..._2?s=computers&ie=UTF8&qid=1529958526&sr=1-na
The Fuma is £55.43 and the conversion kit is £9,82 . The new Rev B comes with the AM4 socket compatibility by PCpartpicker lists no sellers with it in stock. The B is available in US for $45
https://www.amazon.com/Scythe-FUMA-...1?s=electronics&ie=UTF8&qid=1529958608&sr=1-1
Mugen 5 B is available so others should be too
https://uk.pcpartpicker.com/product/8GBrxr/scythe-mugen-5-rev-b-512-cfm-cpu-cooler-scmg-5100
Other Scythe options for MA4
http://www.scythe-eu.com/en/products/cpu-cooler/amd-am4.html
Another perty option in all white but over budget
https://uk.pcpartpicker.com/product/qX6BD3/phanteks-cpu-cooler-phtc14pe
Also this can't happen w/ an air cooler ... don't see it too often but it does happen.
http://www.overclock.net/forum/61-water-cooling/1440506-my-corsair-h60-exploded-water-explosion.html
Leaking H50
Keep in mind that most of our machines are water cooled using custom loops or OLC type AIOs from Swiftech or EK. Just can't see the logic of popping $150 with an aluminum rad, mixed metals, high noise, no expandability , weak (0.11 gpm) pump, performance drop off over time due to galvanic corrosion when for the same price I can get a OLC type AIO from Swiftech that has a copper rad, no mixed metals, no risk of galvanic corrosion / performance drop off, lower noise, better temps, 10x the pump flow, higher pressure, can add more blocks and rads whatever to loop . Unfortunately, availability of Swiftech units is UK is poor. Also way of your budget. The best option I see for you is the Scythe units in the £40 to £65 range
If ya wanna see what mixed metals in a loop does ...
WARNING: graphic photos may be disturbing to nerd and geek types resulting in physical symptoms or emotional damage.
https://martinsliquidlab.wordpress.com/2012/01/24/corrosion-explored/
No quality reviews on the AIO ... all i could take away with confidence was pump and fans on this and similar models from this manufacturer are "far too loud" and component quality is low compared to other CLCs.