There is perhaps one other conglomerate that I see as rich and fit enough to buy United, but a deal would only work if they are properly approached with an offer to build some kind of alliance between United and the other club they have: Mitsubishi Heavy Industries (MHI) - owners of Urawa Red Diamonds and primary contractors to the Japanese government for over a century. MHI may not sound like a full-fledged oil state like the Qataris, Abu Dhabi or the Saudis, but that conglomerate is basically the Japanese government with all the riches going with it. Furthermore, their Japanese club is arguably one of the best clubs in the AFC Champions League (twice winners, once runners-ups, and a 4th final coming later in February). They know what it takes to make a football club successful.
As for SJR, he can go feck himself as the poser he is.