newbie building dozer questions

[dozer]

I am new to the rc consrtuction part of rc but not to rc. I saw some of these machines on you tube and they are awsome. There are some incredable builds on here as well. JUst got a few questions on where to get parts.

Where is a good source for hydrilics?
I have checked out garden trucking and there prices are out of my price range.

Is there a place to buy just the pump i would like to run the pump of an old nitro engine. Is this even doable.