The other big benefit of DIY apart from a massive price difference is that they are easy to repair yourself and also save you the journey to Grimsby or wherever to have it repaired, thereby also losing working hours or days.
Agree.
Back on topic. I don't have a pic to post right now and tbh others would put mine to shame and probably not so relevant as I have a pickup. But some tips ;
Keep pump low
Keep hose lengths and connections to a minimum but leak free.
Same for wiring, soldered if you can, decent crimped connections otherwise.
In line fuses. Finally,, don't worry so much about how it looks. Be more concerned about how easily a fault can be traced / fixed e.g. blown fuse, leak, airlock etc. Its no good something looking neat if you can't fix it easily because its a hassle to get to whilst out working if something does go wrong. Other than cost, for me, this is a big benefit to a tailor made diy system.