ZBrush 4R7. I think they're gonna either drop 4R8 later this year or move onto ZBrush 5
Pixologic :: Store
shyt cost 800 I think, but you can get a student version for like half and they got a free version called Sculptris. Its a lite version of ZBrush, but it'll let you test the waters before taking the leap.
Pixologic :: Sculptris: Enter a world of digital art without barriers.
It takes a lil bit of time to get used to, but once you learn the controls and shortcuts, your creativity gets to shine.
If you looking for tutorials or videos to learn the interface and controls, lemme know and I'll point you towards some good websites to use.
EDIT: I forgot to mention, you'd prolly wanna get a bamboo or intuos drawing tablet like this from a company called wacom
Bamboo
or Intuos (this is the one I have at the crib)
The Cadillac of the drawing tablets and the one's a lot of industry people use is the Cintiq also made by wacom
I think this is the 27HD with touch, shyt runs about 3 Gs
They got a 22HD one that runs for about 15-1800, that's the one I'm saving up for.
You can get a Bamboo or a Intuos tablet for prolly 65-70 on the low end for a small one up to about 4-500 for a large tablet. The tablet really doesn't matter, but those are some of the options that are out there.
There are some knock off brands to the Cintiq that I hear are decent and are alright and will cost you a third of what you'd pay for a Cintiq, I think the company is called Yiynova or something like that.
I had one but couldn't get it to work, so I had to take the L on that one.
I'd recommend at least a medium sized Intuos tablet. You can get those for about 250-300 and it has enough real estate and feels like you're drawing in a decent sized notebook.