Things progressing very quickly on flat purchase, time to look at Utility suppliers!

Got these from U-Switch:
E.ONGas
6.525p per kWh
3.158p per kWh above 2680 kWh p.a
Electricity
23.49p per kWh
10.01p per kWh above 900 kWh p.a
British Gas6.526p per kWh
2.576p per kWh above 2680 kWh p.a
Electricity
22.93p per kWh
8.87p per kWh above 500 kWh p.a
nPower
Gas
2.498p per kWh
Electricity
£84.00 Annual standing charge
7.64p per kWh
EDF EnergyGas
£91.400 Annual standing charge
2.580p per kWh
Electricity
£72.27 Annual standing charge
8.27p per kWh
So with the first two, prices drop the more you use, where as EDF & nPower you pay a flat fee for the year, but then a much lower rate for electric and gas to start with.
Now its going to be 1 bed flat, in a 1930's building with concrete walls and floors, so no thin false walls. I can't see me using much gas for heating, if any most of the year. Only time be used it for boiler for hot water.
I'll run a few IT gadgets, but not excessive amounts (TV,xbox,Mac,Windows PC,Laptop,HiFi,Sky)
Is it best to go for one with the standing charge or without on my usage? :-/