Unfortunately, you are flying out on LX, which mean you don't get access to the amazing SilverKris (SQ J and F only) lounges. You will only get access to the subpar, but still decent enough, Krisflyer Gold lounges. They are only in T3 and T2, and you are better off going to whichever is closer, as they are nearly the same. I've always found T3 to be pretty busy, T2 less so, but still busy.