Roksan K2, Caspian M2 or something else?

I have both of the amps in your title, there both great amps but you cannot compare them together.

if you want a £750 amp the Kandy is good I have mine with some 685s and a Rega DAC and it is good, listen to a few different makes before you decide what is good for one person is bad for another.

the caspian is just a different league of amp and in turn cannot be compared, it is like comparing jaguar xf with a ford fiesta, apples and oranges.  The caspian is a £1700 refined great amplifier that sounds fantastic in a different class to the Kandy.  I have this driving my PM1's and it sounds fantastic to my ears very clear and Concise, musical with a natural feel and flow.  

It is all about your ears and what you like so audition as much as you can and test the units at home so you not dissapointed once you have bought it.  

Lee