Filton would be as good a place as any, as would East Fortune. But at the risk of repeating myself, finding the right site would be a case of "cart before the horse" I fear. What we need to have is a debate about what should be preserved - and properly preserved, not just being drained of fluids and left to rot - and what should be turned into beer cans. To quote myself - do we really need three Vulcans? Do we need four Concordes? Or a dozen Spitfires? If resources are scarce, and space is limited, then surely it makes more sense to keep the last remaining, or single significant example, of a type. I would gladly lose all but one of the Concordes if the remaining one is properly preserved, and the remainder of the money and space was used to look after a VC10 (for example).
Museums should tell a clear story, rather than being, as sadly most aviation museums seem, to be a kleptomaniac's scrapyard. No strategy, just "if it has wings, grab it and park it in a field".
The old Department of National Heritage, long since wound up into Prescott's former megalithic department of Culture, Media and Sport, should be called to account as well. It cannot be right for items of such significance to be turned into coke tins and razor blades like this; if the National Gallery decided it was going to bin a Turner because maintaining it was getting to be a drag, fuses would blow (or at least I hope they would) in the Ministry. Why should our technological heritage be any different?