Budget? Konova sliders and other brands of roller bearing sliders are pretty much the best (as far as dslr use, ovbiously a bigger $1000 one will be better), but the $100 ish dry lin sliders pretty decent for the money. There's lots of videos on youtube about them, i'd recommend it if you're on a tight budget.
What camera will you be using on it?
"you know when you see a edit with there colors boosted and they really hd?" -coleaddison
"When there are more people in your organization who believe Obama is a Muslim than believe in the theory of evolution, there is a problem." -colbert