Personal preference is involved to some extent. I generally prefer to go with air cooling whenever possible, but if I go with water I tend to build full custom loops. The latter would have the best performance, of course.
Since you appear to be building a rig for work, I would think that reliability would be paramount. At stock speeds even the air cooler I linked is more than enough for adequate cooling of an i7-8700K. Even with a mild OC (e.g. MCE enabled to hit 4.7GHz all cores).
If you are overclocking, you may consider better cooling options. A high end air cooler will match or beat most <=240mm AIOs while costing less, so there is also that consideration. The case you have selected doesn't appear to support radiators >240mm so the suggestion of a larger AIO would either require modifications to the case or a different case altogether.