cakePHP on EC2 + postgres on RDS is nice.
toss in some Redis caching and feed it traffic from a load balancer.
you can get a lot done with very little effort.
Using EC2 for PHP and RDS for postgres isn't cheaper with Heroku than with AWS ?
yeh, it is quite a bit cheaper. However, heroku is more aggressive in throttling the cheap stuff. I still use it for ci though. AWS simply offers more granular control and a more robust infrastructure. If you dig down into it, you'll see heroku is actually running on AWS.