How to connect single electric oven, gas hob and cooker hood

[noor29]

I am trying to install a single electric oven and a gas hob, the problem i am facing is the electrics. I have new electrical wiring in my house, the sparky who installed the electric in the kitchen has placed a single socket at ceiling height and a single socket below the worktop which will be concealed by the oven. First of all i want to know if i can convert the single socket below the worktop to a double, so i can connect both the gas hob and oven to that socket, secondly the gas hob i am about to purchase which is a baumatic B68SS states that it has to be connected to a 3 A double pole switched fused outlet with 3mm contact gap (what is a 3mm contact gap ?) is it possible to put a 3 A plug on the end of the supplied cable and plug it directly to a socket, also can i do the same to an oven. The other problem is if i want to isolate the electric i will not be able to get to the socket as it will be behind the oven is the anyway i can add a separate fused switch to the double socket and place it somewhere more accessible and finally can i connect a 3 A plug to the cooker hood and plug it into a socket. I would really appreciate any help as this is driving me mad.