Building your own will save you ~50% ...so if you were to buy retail for 2000.00, you could yourself build just as powerful a PC for ~1000.00.
I personally would look for barebones systems. Benefits of a barebones system: research and testing in regards to "does this RAM work well with this Motherboard work well with this Processor" is done. If you were to build your own, you'd initially spend a good 10 hours researching <--not needed if you don't mind purchasing wrong and then troubleshooting to determine what the issue(s) are.
tigerdirect.com is a good site relating to these barebones systems. Here's a system listied today that I think would work well for you:
http://www.tigerdirect.com/applicati...391&CatId=4910
So this unit would give you: case, power supply unit, motherboard, processor, RAM.
You would need to purchase and insert/install the following: optical drive, video card, operating system.
I recommend also buying a normal spinning hdd for storage of pics and videos.
tomshardware.com is also a good reference for building your own system...here's a link:
http://www.tomshardware.com/reviews/...sion,4024.html