Being serious (I know, on this forum?) with the availability of many Tristars stored in hot places on the other side of the Atlantic, the acquisition of another 6-10 airframes for IFR conversion and a huge holding of spares would surely have allowed the refurbishment and modernisation of the existing fleet for another 10-15 years at much less cost than the Voyager programme. The VC10s could have been phased out as they came to the end of their lives and the RAF would still have a 15+ strong fleet of relatively young tankers fitted with glass cockpits, modern avionics and a full DASS suite.
And yes, I agree that the Voyager is (or will be) a very capable airframe, but the Tristar was as well when it was available. And with the outright purchase of new tankers never going to happen, surely it should have been seriously considered?