Ninka is a good all-round speaker = decent result with budget items before...
Katan is a demanding speaker = not so good result with budget items before... but great result with good equipment feeding them!
Ninka has a lower max level performance.
(Note this is my personal thoughts...)
I don’t have that much experience with Espek (just heard them a few times) but they are very good speakers. Skip the 5140!
This is my advice - FIRST try an Exotik in your house and let the Linn retailer tune the system.
Clearly, the preamp is the weak link the your present setup.
I bet you will be overly excited by the sound using Exotik...
Then... decide how much you intend to invest in the system.
Some ideas...
3*2250/aktive Espek
2*2250/aktive katan + sub
or... if you intend to spend more... Akurate 242
But before addressing the loudspeaker, I suggest you listen to some of Linn’s CD/DVD offerings