My focus, both as a developer and instructor, is HPC, so I have generally been using PGI compilers on large Linux machines. That is also the teaching environment that we provide for students. If you do not have a PGI, Cray or CAPS license available, then OpenACC is not yet implemented anywhere else and you are out of luck at the moment. PGI does have a very nice trial license program, and I'd encourage you to give it a try if it seems at all viable, but that will not answer a longer term access issue. BTW, the PGI compiler does integrate with both Visual Studio and Eclipse, although I personally have very little OpenACC dev hours on either of those.
OpenMP 4.0 (and that is what you need) is currently only implemented in the Intel compiler. 4.0 was only finally approved this past month by the standards committee, so it may take a while for all the compilers to catch up. The big issue here is that Intel is currently only supporting the MIC/Phi architecture for compiler output at the moment. And one can imagine that they are in no rush to change that. OpenMP 3.x is supported very well by MS, Gnu, PGI, Intel and by all of the associated IDEs, so eventually this will all sort out like one would hope.
So, if you want to start developing right now, you will either have to shell out for a compiler and/or limit yourself to certain architectures. Those may be complete non-issues for you. If they are not, you will have to either wait for the situation to improve, or drop back to OpenCL. If so, at least be aware that it has been "deprecated" in a practical sense by the only ones that matter (Intel, NVIDIA and AMD).