The key to ANY photographic image is lighting. There are two possible indoor lighting solutions, studio strobe or continuous lighting.
For anyone on a budget and needing some decent studio strobe equipment, I'd suggest going with monolights, which are separate flash units that are slaved to "pop" when any other flash unit is fired. Look for a unit that can take different reflectors and that are easy to attach modifiers such as light boxes.
A good brand would be Alien Bees.
Followed by a higher level with Calumet's Genesis lights.
After that, a good old pack and head system like the Speedotron Brown Line is great!
Back in 1998 I had a brain fart and replaced all my Brown line stuff with some Novatron stuff. Although Novetron is good, it's not as flexible as a system that can take different reflectors and uses a bare tube head in softboxes.
For beginning photographers I do not recommend continuous lighting. These are typically tungsten or flourescent lighting units, they can get rather hot and really draw the power.
It's easier to get nice portrait lighting with mono-light strobes.