Not exactly ideal but I had to pay the additional £5 a month for a static IP.
For any other people that might be looking at doing something similar, I used my old router (this isn't really capable of the 150Mbps WAN speed to I'm going to upgrade it soon). Simply plugged the Hyperoptic cable from the wall box into the WAN port on the router - literally worked straight away with very little setup.
To get around the VOIP issue as I have the calling package too I purchased a Grandstream HandyTone 801 (http://bit.ly/2yuoEy3
) which I set up with the SIP details acquired from Hyperoptic.
So my system is now back up and running!