With a system like yours I’d fit decent fans (low-noise ones, peferably oversized with air tunnels to interface with the vent holes if needed) and use vacuum cleaner filters (or cut sections of a cloth or decent paper vacuum cleaner bag to fit, but this will likely restrict airflow more) on the intakes; inspect and clean or renew as necessary on a regular basis. This WILL significantly reduce crud ingress therefore less heat stress on individual components & also help to dampen the fan noise.
Water cooling does have its merits but also some dangers … for obvious reasons. It might be necessary though with such a high-performance system and in this case a top-mounted (or rear-,mounted) radiator might be a good solution depending on the case design.
My old “performance” PC (stolen about 10 years ago) was used with the side off as the big heatsink assembly wouldn’t fit in the case without cutting the side panel and adding a protruding grille. The CPU fan was an oversize one (8" I think) on a massive heatsink and it was only a quad-core @ something like 3.2GHz.