Welcome to the macro gang
Most of us design our own diffusers powered by a flashgun and the results will be a lot better than any ring flash/light at a fraction of the price

Personally I think the ring flash (not ring light) will not be very good for macro because it limits the subjects you can take (generally limited to very upclose shots), and the very close distance of the flash to the subject means that you have no place to put in any DIY diffuser for extra diffusion (which you certainly will) in the future

Save the money and design your own DIY diffuser, you will be amazed at how big the difference will be~
Here are some of my earlier diffuser designs, perhaps they can give you some ideas: Pixelsdimension- My Macro Setup 2

You will need some extra money for Raynox-150 or 250 later on