Dedicated listening room set up

I am in the process of moving and will be setting up a dedicated listening room in a new home.  My current system consists of Spectron III SE monoblocks, Modwright Tube Preamp, Sony 9000SE SACD, and Clearsudio Emotion TT with either B&W 803s or PSB Synchrony One's .  In this room I am going to use a dedicated circuit on a side wall for the components with speakers on a perpendicular wall which will differ from my previous setup which had the components between the speakers.  The issue is - 1) should I increase my speaker cable lengh from 6' to 12' while keeping monoblocks on the side wall or 2) or would it be better to place the monoblocks close to speakers and run longer interconnects from preamp and shorten the speaker cables to 3' where i will also loose the advantage of using the dedicated circuit for the amps.  The reason i have decided to do this is because of a prior experiment which resulted in a better listening experience.  It has been a while and although the exact differences are now a little foggy i remember how much I liked the result.  I have since read that it is wise to keep the Amps close to the speakers thus my question.  I do realize much of this is peronal preference but was just wondering if anyone had experience with this setup or advice.
Thanks