I think that the Manual (fixed or by weight and by total) Plugin would be a problem for Zone shipping for the UK because there are so many postal codes, and the plugin cannot do ranges/wildcards. There are plugins in the marketplace that can do zone shipping. For example,
Shipping Director can "calculate" zones and then assign the zone to its built-in variable $DestinationZipPostalCode, which then overrides Destination Zip/Postal Code that is sent to other plugins (like fixed or by weight).
As an example, you could
a) set up Fixed or by Weight with zones in the Postal Code field ("Zone 1", "Zone 2", etc.)
and then
b) set up Shipping Director rules like this (pseudocode)
Zip2 = Zip.Substring(0,2)
if "AL,CB,CM,CO".Contains([Zip2]) then "Zone 1"
if "BN,GU,HP,ME,NN".Contains([Zip2]) then "Zone 2"
...
call Fixed or by Weight to get methods/rates