wrote on Aug 29^th, 2009 at 11:03am:

Yes, they are essentially the same device, as I said, the names for the different devices has become a bit muddled up in the last couple of years.

So the answer to Paul's original question (assuming he hasn't given up by now) is that he can buy either (and if he so chooses, either of the actual models we have mentioned), plug the ethernet cable between the device and the socket on the Iberbanda network box, his voip phone into the other and he's good to go (as our cousins accross the pond would say).  By the way, they helpfully throw the term "gateway" into the mix.
As to cost, looking on UK sites there's not much in it as far as RRP goes but older (but adequate) models might be discounted.
I'm assuming that Paul has more than one wireless enabled PC/laptop that he wants to be able to access the internet with as otherwise there's no point.  I currently have my PC plugged directly into the router as the comm speed is higher and just have the laptop wirelessly connected.