RF2 should work fine.... What kind of interference?

Is the delay problem just with sky or with dvd's too? What kind of TV / sound system are you using? Plasma tv's have a processing delay in the order of 10-30ms depending on design (and price!). If you have no digital processing in your a/v amp then there is no latency, therefore sound will come out before picture. Most digital a/v receivers/amps include delay adjusment (often under the title of 'speaker distance'), which you could try fiddling with.

What connections are you using for audio and video?

Chris