I'd recommend Pivotal Web Services[0], aka PWS, aka "p-dubs", buuuut that's only because I work for the company running it :)
If you have a 12-factor app that pulls config from the environment, it should ideally not be too traumatic. Services are meant to be injected by the platform.
Apps should be the easiest part. Of the buildpacks: Ruby, Python and Node are based on Heroku's and are very nearly identical. Go is based on a community buildpack, PHP is a complete ground-up rewrite and Java is a ground-up rewrite maintained by the Spring team.
If you signup for PWS and you find things broken or missing, email me: jchester@pivotal.io, and I will find who can help you.
[0] http://run.pivotal.io/