I'm trying to get into macro as well and I've bought a reversing ring and got my hands on an old 50mm f/2.8 so that I can mount it backwards.
Of course, it's not exactly fool proof and requires a lot of effort as there is no netering and the only way you can focus is to move the camera backwards and forwards but it's cost me less than £20 and the results are pretty good.
Click to EMBIGGEN
Click to EMBIGGEN
As for a ring flash - do you have a flash gun? If so you can get ring flash tubes which fit over your flash gun like
this one