BenNguyen

you can try using a pump and res comb that sits on the floor or secure it somewhere in the other compartment

It depends where you want to install it but you can either make a custom plate or drill holes and bolt it through the rear side of the motherboard tray. 

yea that what i have, and still waiting on EK to deliver my res+pump cooler the tubing is here, the 1080 is already here #feelsslowman

The air 540 isn't a bad case to watercooling in, it's quite capable of holding either dual 240mm rads or even a 240mm and 360mm as long as the rads are thin. 
 
For the res unit, if your lacking space in the front side you can always go for a small res in the rear portion which I have commonly seen. 

Moto360 is love moto360 is life. I'm fanboying here but I love this watch

recycle by resell or donate it to people or use it as a monitor stand or a tea cup stand