Thanks to all for your comments.
The second drawing with 4 launchers was always the least likely. Fitting the command and control functions would require a purpose built ship with space being provided for everything required. The Vanguard while big enough would require almost a total rebuild to fit everything in. Cheaper and quicker probably to build from scratch. So No.2 = 'No'.
The first drawing is fairly decent as is but needs internal reworking to add more things like electrical generation. Removing all the aft turrets and fittings like the armouries does allow more space to be allocated for electrical generation. So that side of things can be catered for. The requirement for a conversion is how much can be done as cheaply as possible on a 15 year old hull.
JSB - I can probably raise the target designators to give some height separation. I did look at having a chopper and hangar aft, but in consultation with Hood, he advised a helicopter arrangement was probably not needed as the ship would have plenty of others around that could supply helicopter services. All Vanguard would require is a circle on the aft deck somewhere. With the 3"/70, I actually removed 8 twin mountings and replaced four of them with the 4"/54 mountings. The 3"/70 never had a good reputation so replacing it with my AU 4" auto, which of course is a brilliant gun, makes sense.