Well have now got the DSL-2740B and must say it has done wonders, for both ADSL and WiFi!
ADSL SNR Margin is now not going mad anymore! Keeping at a stable rate so that is great!
Also, Wireless N is great in my house, can use wireless anywhere now, even in places I couldn't before, as well as in the garden on my iPod Touch!
Overall I am very pleased with the router and many thanks to Azzaka on your advice regarding chipsets, most appreciated
Cheers
Jamie