IT was a powerful gathering of impressarios from the Asia-Pacific region that assembled in Hongkong earlier this week to cut deals on the forthcoming tour of the Pomade Pink One (aka Michael Jackson). But none could quite match the style of mega-rich Singaporean businessman B. S. Ong. Ong - who holds the Hard Rock and Hollywood Planet ''attitude eaterie'' franchise for our neck of the wood - jetted in from Tokyo in his customised Lear and whisked Jackson's manager, Jim Morey, and his wife Trudi and German promoter Marcel Avram, who holds the worldwide rights for the forthcoming Dangerous tour, over to Singapore for dinner and discussions about the concert there. Jackson will arrive in Singapore for two dates straight from Brunei. But what of Hongkong? If the t's can be crossed and the i's can be dotted on a potential deal - only a few key logistic details remain to be ironed out - it might be that Jackson will kick-off the tour in August in Hongkong. Let's also say that when Jackson's team arrived in Hongkong one of the first things they did was to call a well-known local tycoon and pass on the warm wishes of Jackson's personal physician. As it happens their man and our man both share the same Beverly Hills doctor.