Nice system. I too used to own MF and Monitor Audio (A3cr pre-amp/amp and Silver 5is). Sometimes I wish I would have kept the 5is around for use elsewhere around the house but eventually sold them to upgrade.
Try the VH Audio power cords. I'd recommend a Flavor 4 on your amp first. Unfortunately there is a long break in time (100 hours), but you could be surprised with the results with this affordable cable. Also look at Paul Speltz anti-cables for your speakers, they are amazing.
Good luck!