I have something that I use that may be a little more encompassing then what you are asking for but it does include login role membership and object permissions. You should be able to get what you need out of it.

The code attached collects role and permission info across multiple databases so if you want to use the code as-is you will have to create all the tables in the script as well as linked servers to any of the servers you would like to audit. You will then have to populate the servers table with the servername(s)/linked servername(s) you wish to audit.

note: this is a work in progress so some columns may not get populated.