Of course, I might be just a teeny bit biased, but what about flying with the one and only, the great, the unequalled Cathay Pacific. You could stopover in Hong Kong on the way out or back; you could also stop in Bangkok (one Cathay flight stops in BKK between HKG and SIN) AND - perhaps most importantly from an enthusiast's viewpoint - you could take in more different types. SIA would be a terrific choice, no doubt about it, but it would be 744s all the way. With Cathay, you could fly on a 777, A330 or even a 773.
Of course, have you considered Korean Air via Seoul?
Er, mm . . not, let's stick with Cathay . . .