Wow Gents, thank you very much for all suggestions and advices. My room is very small I believe, from around 13.5-16.0 m2 I believe, therefore the speakers' position is the best I can get in this room. Even I wish my place was bigger but this should be in the future when I finish my PhD and move house.
Regarding valve pre, I see many people using AR REF5 pre-amp so this amp might be in my consideration. I see some other brands which are highly regarded and recommended such as: Ayon, Lamm, Conrad Johnson, Einstein - my very interesting pre to be honest - Wavac, Audio Note/Kondo,Allnic, BAT, Nagra...
So there are so many choices, but I am after s/h or ex-demo products only. In case I have to purchase sth brand new I dont want to say good bye so soon :P as I always do, therefore your knowledge and recommendation is very important to me.
In the UK, it is quite difficult to get home demo with one of the above brand/equipment. 99% equipment in my system has been purchased blind without any inspection or audition. This time I believe will not be an exception.
In fact, there are also many other ss pre-amps very good out there, but as I said I have never tried valve in my system, hence this time I hope I can get a pre home.
many thanks and best regards,
SR