Totally fresh in the world of mechanical keyboards. So far I don't even own a mech keyboard, but that's about to change next salary

Got into this though researching ways of simplifying my computing experience. I have this vision of a small, battery efficient SSD laptop (maybe some linux tablet?), loaded with a custom linux build based on the Ubuntu Minimal CD install. Thinking I'll go with i3 window tiler, vim and some other bits and pieces. Add a customized mechanical keyboard to the keyboard driven system and voila!
I'm looking at buying a German Poker II PBT w/ MX Blue switches, order ~"WYSE" style keycaps (two-tone gray, yum) in Swedish/Finnish layout, 2mm o-rings.
Like the idea of JD40, a 40% board, but I need Å, Ä, Ö as standalone keys. Any other 40% boards out there?
Need to figure out what the best choice of computer would be. Really want to find some tablet which is possible to format and successfully run linux on. Portable, power efficient, minimal 'one thing well' computing without crumby laptop-keyboard in the way. Mainly for text editing, writing. If you know of such a tablet, please do share!
Robin