I believe in not inventing the wheel;-) That’s another incarnation of DRY … So a good starting point for AMI images are the ones of Rightscale.
RightImage v3.0 (32-bit, 64-bit)
Release Date: June 17, 2008
Nickname: RightImage CentOS5_0V3_0_0
IDs: ami-d8a347b1 (32-bit), ami-c8ac48a1 (64-bit)
Locations: rightscale_images/CentOS5_0V3_0_0.img (32-bit), rightscale_images/CentOS5_0V3_0_0.img (64-bit)
Use the 32-bit version for m1.small and c1.medium instances. Use the 64-bit version for all other instance types.