Any type of reversing lenses (either reversing one on top of another, or using a reverse ring) will be a lot more practical if you have a lens that features an aperture ring.
The good news is that there's a lot of manual lenses like that are pretty cheap and really sharp! And inverter rings aren't expensive, I paid about 10 dollars for two (one 52mm, one 49mm) from KEH.
Here's my suggestions...
Pentax-M 50mm f/1.7 - about 40 dollars, will give you about 1:1 magnification. I would start with this.
(you could also get a RIkenon 50 1.7 or f/2, or an Auto Sears 50 1.7 for about 25 dollars - those are also excellent lenses)
I use the 50s at about f/8 or f/11.
Sigma Mini Wide 28mm f/2.8 or Rikenon XR 28mm f/2.8 (a bit more rare) - from about 30 dollars, will give you about 1.7:1 magnification - that is HUGE in practice and you will probably need to stop down to at least f/16 for get a good part of the picture in focus, and use flash to make this work. You'll also have to compose almost in the dark, because of this.
I'm still starting so here's a couple of examples I did with the inverter rings.
First one with the 50mm, uncropped:
Now one with the 28mm. This is salt on a countertop, I did cropping on this one:
And this is a henbit flower stem with the 28mm with not a lot of cropping:
The 50mm was done without flash, and the two 28mm were done with just the onboard flash.