I would get the SSD. It'll actaully affect performance, where you can use air cooling to get the same benefits of liquid cooling. You can't get the SSD's performance by using anything else.
Also, liquid cooling only looks cool if you do it right, which takes a lot of effort. If you're new to it, it also increases the risk of damaging something and ruining the build. I always recommend sticking to air for the ease of use and installation, not just because it's a lot cheaper.