Okay, first, quick update on things.
As per recommendations, I purchased a Coolermaster HyperEvo Plus, for my AMD Phenom II X4 3.4ghz CPU installed on my Gigabyte AM3 motherboard. Since then, I've managed to safely install it, and have overclocked my CPU to 4ghz, where it operates at about 36c idle and 45c under load. I am reluctant to overclock beyond those numbers, because I've not yet has an oppertunity to test the CPU under a sustained load, so I have no idea if those numbers will still look so good after 4-5 hours of strain.
I've also overclocked my AMD Radeon HD 6850, from 750mhz to 825mhz, and tested it under sustained load, where it seems stable. I've also tested it at Max overclock, where it ads another FPS or so, but on stock cooling I wouldn't trust it to stay cool after several hours.
Now, the game I'm most concerned about at this moment, is Final Fantasy XIV 2.0, Using the above components at these settings, I've been able to get the game to run anywhere from 24-35fps at 1080p at max settings, to 51-55fps at 720p.
This is about a 5-7 fps improvement on both settings, over when these same components were running at stock speeds.
Ideally though, I'd like to be able to run this one game at 1080p, at max settings, at 60fps. This is actually probably my biggest priority in gaming for the entire year.
What I would like to know, is if there is any singular component I could replace on my set-up, that'd allow me to do this. I can scrape together enough money to replace the CPU, GPU, or to add a boatload of memory, but I cannot afford to do all these things before the official launch.
Now, I've got to point out, than long term future compatibility, isn't a big issue. The PC is usually where I go to play games that're a year or three old, after they've been heavily discounted. The only titles coming out in the next year that I plan to pick up on PC, at launch, are FFXIV, and Dark Souls 2, and I don't expect the later to be particularly demanding.
However, assuming I scrapped together $175USD for a new mid-range CPU, would it make that kind of difference? Or would I be better off saving my money until I could make a more comprehensive upgrade?
Edit: Yes, I'm quite astounded that Square's gotten this to run as well as it has on the PS3. It just shows you how far optimization will take you.