One wonders why, given that we are getting some Gucci new tankers, we didn't just buy some A330 airframes and add the relevant systems? A330 has high altitude, long endurance/range, plenty of available conditioning and electrical generation, space, ability to carry plenty of GSE/people when deploying, space, commonality with Voyager etc. Too late now of course, but just a thought.
Mate, that is incredibly naive, if I may be so bold? Have a look at the picture below. Just how difficult do you think it would be to cut metal to accept all those antennae and the 2x collosal arrays just in front of the wings? Furthermore, increase the output from the generators to power all the new kit and also increase the cabin conditioning? Then adapt the wiring looms, the conditioning trunking, cut holes in bulkheads and aircraft skin, conduct an EMI survey and then ensure that it is secure from emitting its secrets to snooping recievers? You are looking at years and lots of £££s.
Unless, of course, you were hoping to deliver a capability in 2020+? Probably late? And definately over budget...
LJ