Okay first off, DO NOT tell me it's overly difficult or expensive. Thanks.
What I want is a sort of 'bare bones' laptop case with a motherboard and maybe battery. Let's say price is no obstacle, I want to do this for the the fun of building a PC but I need the mobility of a laptop. I can't have both a desktop system and a laptop, either. What are my options here?
I know about the 'no standardisation' problem and I've asked about case with a motherboard, the two parts that are generally most problematic with this sort of build.
Closest you get is a high end gaming laptop from the likes of MSI or Clevo. You can get a chassis (case, keyboard, motherboard and screen) where you get to choose various options from processors, graphics cards, wifi card, memory, hard drives and optical drives. What you receive is a built laptop with the components you have specified. You won't find a reseller who will sell you the components and let you assemble it yourself.