Only Programming Computer no games running Ubuntu

Approximate Purchase Date: within next month, could be next week if i find a good deal

Budget Range: under $500

System Usage from Most to Least Important: Mostly I'm going to be using this for programming. I'm learning new programming languages and practicing with them just trying to teach myself through books and online tutorials to see what i like best before going in depth with learning a lot about one of them. I would like to have a dedicated system for this to keep my family computer available for the rest of the family. The most video it will get is youtube or maybe a blu-ray. I would like to be able to have offline versions running on my computer so i would need to be able to run mysql, php, ruby on rails, apache, iis, "c, c++, c#" compilers, java, python, perl etc. I think you get the point of what programming languages i mean.

Parts Not Required: keyboard, mouse, monitors, speakers (going to be ubuntu system so will not really need OS)

Preferred Website(s) for Parts: newegg.com, microcenter is also close and i can pick it up from there.

Country: best possible place they can be i don't know any better to be honest

Parts Preferences: best available with budget

Overclocking: Maybe nice to have as an option but not looking to anytime soon

SLI or Crossfire: I want quad monitors in the future but plan to start with dual. This is so i can have 4 screens up. (FTP, Web server, programming window, file system on computer) Anything that can make this happen without dropping more for the cards than the system itself I'm open to.

Monitor Resolution: best available

Additional Comments: I just don't want to get too cheap on this where it gets slow while running, id rather spend a few bucks more to make it "stable" and usable.

Everything i look at online gets such mixed reviews because it seems like most builds get centered around gaming. I wont be needing nearly the processing power in my opinion and the video card demand.