You can use SageMathCloud. It is a cloud service entirely based on Sage (which in turn includes R) and LaTeX.
As you can see, you can mix up various cells with different languages. In the picture I have put a
%latex cell and a
%R one. The default of course is Sage, but you can also use
%md for Markdown.
While you are in R mode, the IDE offers you some code snippets:
Regarding your requirements:
An accessible manageable file system
The website is based on Linux servers. You can access your home directory and configure it, including changing the
.bashrc file, installing Python packages and so on.
Some way to connect to online git / subversion repositories
You can access your projects via SSH with any plan (including the free one) and use
git locally. You can access arbitrary network locations with the paid version of SageMathCloud.
Console access for when i need it
Yes, either connect via SSH or create a terminal "file" in your project to access a shell.