AMD's tech docs on their website tell you the exact max temp. for each model CPU. I believe the 1100T is ~62C or 65C but it may be a little higher. Make sure to use Core Temp to measure your temps as some software gives false temps.
The link below shows cooling performance data for many of the popular heatsinks. Read the full HSF review for clearance concerns. If you have room the CM Hyper 212+ is an excellent mid-range cooler at a great price but there are also some good, smaller HSFs too if the Hyper 212+ is too large for your case.http://www.frostytech.com/top5heatsinks.cfm#AMDHEATSINK