tvLink and digisender and Masterplug question

I have a digi-sender to the bedroom upstairs and a cable running from the skybox in the sitting room to the living room. To change channels in the living room, I was thinking of getting a tv Link or magic eye thingy.
Can this work with the digi-sender also on board? Is there a specific set-up required?

Also, what's this 'Masterplug' 3 room viewing kit they have in the new Argos catalogue? (p. 642) It says you need an additional coax cable, so how is it different to just running a cable off a splitter to supply two rooms? I know it has the magic eye inbuilt, but that seems to be the onl difference?

Thanks in advance.