@AlanUKWatson 

 I think this can be done, I did a few google searches and found some useful links, most were from the Sky community forum. Its worth having a go once you do change over to FTTP. I was going to put a link here to the one discussion I found that had the best explanation but it won't let me paste my link for various reasons.

There are a number of other discussions from google search that may help. I don't think Sky will help you at all (with any settings) as they only really want you to use their own router. :-)