I was expecting a request for something like a 40%-75% but ok. I can't help much when it comes to a TKL, 1800, or full size but I'll try my best. Sorry.

First problem here is the numpad and media keys. Full sized customs are hard enough to find, let alone one with dedicated media keys. The closest boards I could find are the KBD19x and KBD8x. There are more boards but these are the ones I can find that are retally available and isn't too expensive.

The nordic layout is less of a problem but still a problem, if the keyboard has a physical ISO layout then getting a Nordic keycap set and reprogramming it will make it a Nordic keyboard.

For the switches, yeah MX Clears are maybe the right switches for you. Maybe Zealios V2s with MX Black springs?