This computer is half new parts, half old parts. You can clearly tell that the older parts are the RAM, CPU, and Motherboard. While the CPU is still fairly modern and does its job well. This is still a solid computer, and I'm looking for advice on the max amount of money I should put into upgrading this machine. I'm currently looking at;
Wait for Bulldozer. If you upgrade now you'd just be wasting money. So... With that said it'll be 5 days to a month. It's uncertain at this moment but BD should release soon especially with the B2 revision breaking the world record overclock.
The 1100T will not give you much increase over a 955 so yes it would be better to wait a month and get a Zambezi CPU which should be a healthy increase for only a bit more than the current price of the 1100T. The Gigabyte AM3+ mobo is a good choice.
When you buy new RAM get ONE tested, matched 8 GB. RAM kit of 2x 4 GB. 1866 Mhz. DIMMs as Zambezi CPUs run RAM at 1866 Mhz. by default. Currently you can buy brand name RAM real cheap so 8 GB. should be in the $70-$95 range depending on what you pick. You don't need heatsinks on DDR3 RAM and they can interfere with your HSF so chose wisely.