The new Subversion 1.8 features look quite good for a centralized Version Control System (VCS).
But note that the Subversion 1.8 working copy format is backwards-incompatible. Some tools like recent TortoiseSVN versions will use the 1.8 format by default which will cause compatibility problems for IntelliJ and any other tools that do not yet support it.
So for now, it is probably better to stick with 1.7 and wait until all your tools fully support 1.8. For IntelliJ you might want to watch [IDEA-94942] for status updates.
About Git, compared to alternatives
A very useful post on stackoverflow:
Typical problems using Git in corporate environment with solutions
Linus Torvalds’ famous “rant” style presentation about Git vs Subversion:
Questions, discussions and answers on stackoverflow.com:
Distributed Version Control Systems and the Enterprise – a Good mix?
Can we finally move to Distributed VCS in Corporate Software?
Git-Based Source Control in the Enterprise
Reasons against using “Git” in the enterprise
Article: “Benefits of Git for business” (from 2008 but still valid):
Presentation: “Git for Companies” (Video and Slides, from 2012):
Pre-tested commits with git and Jenkins: