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.http://www.newegg.com/Product/ProductList.aspx?Submit=ENE&N=100007611%20600006069%20600006130&IsNodeId=1&name=DDR3%201866%20%28PC3%2014900%29