this kona or this principia advice welcome

Thanks

For the money I'd get the Principia, although be aware they've since gone bust and although they're now trading again I don't know how you may get on if you ever had problems or needed mech hangers etc.

They're also quite 'Euro-roadie' style, long top tubes, low front ends, light and racey.

The Kona's much more of an all rounder, but is much lower specced. I'll wager there'll be less interest in the Principia, which IMO would be another reason to buy it!

When I was looking at the sizing charts they were both suitable for me at 6'. 

The Kona with a long post and the principia not so.

Go for the Principia.

Even if the frame doesn't fit, you can ebay another frame that will and have good spec bike for not much cash. You would have to spend a crapload to get that kona speced to a similar standard.