Since you are getting the 30D body, i.e. 1.6x crop, you may consider the following combo.
1)
EF-S 10-22mm
This is an unrated, hidden L lens. It's meant for the 1.6x crop cameras which will give me the perspective of 16mm on your 30D.
Moreover, it has 1
S-UD and 3
AL glasses. Like an L lens. ;p
http://consumer.usa.canon.com/ir/controller?act=ModelDetailAct&fcategoryid=148&modelid=10510
I owned these lenses, EF 17-40mm f4L, EF 16-35mm f2.8L and EF-S 10-22mm. Eventually, I sold off the first 2 lenses and keep the last one. Why? not because of optical quality, etc but because of the perspective that it gives you. Unless you have a FF camera, then you may consider the EF 17-40mm f4L. If you have more cash, then get the EF 16-35mm f2.8L. Based on your feedback, you are on a budget, do you?
2)
EF 24-105mm f4L IS
A newly launched lens. Yes, it's quite expensive, almost $2,100. Having said that, it's a good lens for general purpose and street photography.
Not forgetting, it also has 1
S-UD and 3
AL glasses. ;p
With the above 2 lenses, you can still bring them out either when you are in Singapore or traveling overseas. The weight is 385g + 670g = 1055g
If you want to buy the EF 24-70 f2.8L, you may want to consider its weight. Just one lens weighs 950g. Are you sure that you wanted to bring this lens overseas for traveling?
Try out the above lenes before you decide whether you should get the EF 50mm prime for portraits. How many times r u shooting portraits? and whether 50mm is the range that u like the most? Use a zoom lens to start first, and you will know which focal length u always or use most of time. Only after which, then you will consider prime lenses.