Louder? So just because a card is larger and graphically stronger you assume it's louder? That has absolutely nothing to do with it at all. You really need to stop giving people ''advice''.
As for AMD VS intel....the upgradeability thing is BS on AM3. People have said this time and time again. But things on motherboards keep improving, so therefore just being able to slap a newer CPU in an old motherboard is still bottlenecking your new CPU. For instance, in some of the older AM2 boards, you can run AM3 cpu's sure, but hyper transport will be cut in half. Plus, DDR2 ram is way out of date now. Soon there will be DDR5 ram, and then Sata12gb/s, and then USB4.0, or whatever who knows. Newer chipsets are better at overclocking, the SB850 has faster transfer rates for RAID, etc etc. Point is, upgrades to motherboards happen ALL the time and every year, so stop saying that you can just buy this board now and upgrade the CPU later because there WILL be bottlenecks somewhere.
Bulldozer is gonna have quad channel memory, and who's gonna want to run one on an ''old'' board with dual channel? The CPU itself is going to be bottlenecked in a lot of ways on current AM3 boards. Hyper transport will be bottlenecked as well I'm sure. AND anyway this is under the major assumption that bulldozer will in fact be compatible with any AM3 board to begin with, something I seriously doubt will happen.
That being said, you don't really NEED a hex core at all. An I5 750 would do all you need and way more, it's a very powerfull CPU. And by the time you would NEED to upgrade, it won't be for a couple years anyway and by that time ANY pc is vastly outdated and not really upgradeable anymore.