Hey if you can do a few things to make it easier for us
1. Make a rig setup in your' profile go to user profile --> Scroll to the bottom --> Click " Your Rigs" ---> Click Create a Rig --> Fill it all out and save it up
2. Are you flexible on your budget? What type of monitors do you have? Are they 1080p, 1440, 1660p? What size
3. I see that you're a coder and do graphic arts. your system is REALLY REALLY old, would you be flexible on your budget? Even a few hundred more can go a long way.
4. Case, Do you plan on updating this case or building again in the future?
- Case wise, if you can take photos and post them here it would be helpful, since I am not sure what mobos you can use.
5. Windows operating system wise, it does help but not by much just shows us that you are in x64 (you are right?)
6. I would recommend parts wise if you cannot upgrade with more money, using the forums For Sale / For Trade section. Check here, hardforum, anandtech to find a good deal.
- For example, I am in the process of upgrading as are many people potentially in September for the LGA 2011 and new Haswell builds. all of us will be unloading our old hardware. In my case an i7-930 / x58-ud5, GTX 460 (I just got SLI Titans), Power Supplies for new hardware, old monitors i.e dual 23" and you can most likely get some REALLY good deals. Significantly more so than if you bought new.
The only problem with this route is that if you are keen on FULL Warranties, don't know how to build (not sure based off your premade system), this could cause you a lot of problems. If that's the case, buy a cheap laptop connect your monitors to it and be done with it. You just won't be able to do much.
Moving on to more specifics:
1. GPU, you can get a GTX 460 for around $80- $100 used, or a 600 series for $150-$250 used
2. CPU / Ram / Mobo - New you are looking to spend a lot, used you can get good deals, I feel an older i7 series or i5 would be more in line with what you have.
Someone in Hard forum is selling there i7-950 and Super Micro case for $200 just has no ram
3. Hard Drives, what do you have now space wise? Do you find you are running out of space you can get 1TB Hard Drives for $50+