Re: Travelling with 9mth old to Aus
agree the with previous posters, long stopover or none at all. did this trip once with a three month old and then again when bub was one. did 2 night stopover on one trip and no stopover on other. unless you are really staying at a nice place and can relax, i would recommend direct.
there is always so much luggage travelling with an infant and unless you are breastfeeding you have to make sure you have access to clean water at all times. we wanted to stay in singapore for a couple of nights when bub was really small but opted against it because it had a small dengue fever outbreak. i know, probably overly paranoid, but when they are that small you don't want to take chances (on that note, make sure his/her immunisation schedule is up to date).
we flew with emirates and singapore, both excellent. singapore is a child-friendly airport and you can take a quick dip in the pool at the airport hotel (about $10 from memory, kids free, don't forget to take the swimming nappies).
have flown thai before, albeit without kids, but seemed comparable to both singapore and emirates.