Building something like Anisoprint Composer A3?

Where should I be looking to learn more about peoples actual 3D printer builds? I'm sure there are great well-established forums out there. Can you please give me a few suggestions?

I would like to build something with a large print area so I can print molds for carbon fiber parts or maybe actually the parts themselves. I am new to 3D printer, but I have some software dev experience and other related things.

Right now I am trying to look into the possibility of making something along the lines of the Anisoprint Composer A3 or their PROM IS 500. Not sure how possible that is, but there are smart people out there in these communities so nothing would surprise me.