Hi, in your case the replacement XTE2005 faceplate would be wired up exactly the same as your existing faceplate. So take note of the colours and connection numbers (typically BLUE/white >2, WHITE/blue >5, and optionally the ringer cable ORANGE/white >3 )
And as the two sockets on the front of the XTE2005 are filtered, as well as its extensions you'll wire in, you'll no longer need any Sky soap on-a-rope filters
I'm not sure from your post if you're using a wireless link between your router and your PC, but if so, this could be a problem area if you're serious about download speeds. I finally gave up on using wireless for my main PC as any slight loss of signal would dramatically affect your final download speed. I would now only use wireless connections to easily connect laptops to the network when required. So I ended up running a high quality long modem cable
(link) from the ADSL socket on the front of the XTE2005 to my router, it's now rock solid.