EDIT: Actually, since you have never done studio work. I really recommend you do a course before buying anything. That way you can learn exactly what you need without having to buy twice.
I also think that 30k is a bit tight. I am going to use Canon for most examples - even though I use Nikon

Canon is going to work out a bit cheaper here... I wouldn't spend 15k on a body though - for portraiture on a budget a cheaper body would suffice. Something like the 500D for about R7k. Good glass is more important than the body - you need something fast like a 85mm/105mm. Pro portraiture photographers generally prefer something longer than 35/50 to avoid distortion by moving to close and to give the model a bit of breathing space. I watched an interview session a while ago, and most of the togs preferred a fast 70-200 type zoom. This will set you back between R7k - R25k. A 85mm f/1.8 prime is around R4k for Canon, a bit more expensive for Nikon. Then as mentioned you need a proper tripod and head, another R5k at least (good legs go for around R5k on their own). So a relatively basic body, 85mm prime and studio level tripod totals to around R16k.
Proper lighting also don't come cheap: R3k - R6 each for the sort of soft boxes you would need. Modifiers for other lights (background etc) like snoots/grids/barndoors are around R1k-R2k each. Then you need the reflectors/backdrops/flags/pocket wizards etc for probably around R5k. In a studio environment a separate light meter is important, the entry level Sekonics are about R3k. So a simple 3 light setup could easily cost (without getting quotes

) around R25k. That said, you do get basic Elinchrom Studio To Go kits (containing the softboxes, umbrelles and lights) that might work out a bit cheaper...
Then the software, Lightroom 3 retails for about R3k and I guess you have the computer already. So that is around R44k for a basic setup, which is pretty much what flarkit also said. Since your brother's studio sounds pretty important I guess they will be expecting professional results? If so, you definitely need to go on a studio course, especially since you are used to nature photography.
Good luck - hope this helps
