This will be my second custom-built PC, and the first one where I picked the parts myself, so I'm not sure if I know what I'm doing. The plan is to build a PC that can last me 5 years without major upgrading.
CPU: At first I had the i7 4770k but switched to the i5 after some further reading. Besides gaming I'll also be doing some sound editing, but I think an i5 can handle it well enough.
Motherboard: Went with one with high ratings and all the rear ports I wanted. Also Microcenter has a combo deal with this and the i5.
Memory: 8gb seems enough for now, will upgrade to 16gb in the future, if needed.
Video Card: Decided to shell out for the 780, which hopefully will run games near-max for at least 2-3 years. After that, if I really need to, I'll get another 780 for SLI. Currently I'm only using a single 1920x1200 monitor but I do plan on adding another one sometime this year.
As for budget, I can go up to $1500, although I'd prefer to save some to invest in a quality sound system. Any suggestions are welcome.
You've got the memory thing right - it's rather expensive (comparatively) right now, so wait on that.
You are also right about the processor - the i5 will carry you a long way, probably won't need to overclock for a while as well.
The 780 will run games on max for years to come (the console market has stagnated, and will continue to stagnate innovation in gaming) so no worries there.
Nope, you've got a great thing going there. Nice work.