Which has the better network coverage in this area, - T-Mobile or O2 ? I bought a cheap mobile today and can put any payg sim card in it, so I'm looking at Easymobile [T-M] or Tesco [O2].

Easymobile is cheaper @15p/min to Tesco's 20p/min but it really depends on network coverage and I've heard that T-Mobile is quite poor in some areas.

it depends where you are. I had o2 for a while in the norfolk park area and it was good yet it was poor closer to the city and the exact opposite for t-mobile. Vodafone is your best bet wherever you are.