As a Silvia and Rocky owner, I'd say Wookie has pretty much nailed your options: Rocky, Vario if you can stretch for it price-wise, and if you're a little adventurous, like the idea of commercial grade grinders, etc., find a used commercial grinder (like a Mazzer) and replace the burrs.
One note -- Rocky and Vario can easily be used to grind for other brew methods (french press, drip, etc.), and then switch back quickly to espresso. A used commercial espresso grinder will not be that easy, if you can even get a good non-espresso grind out of it at all.
If you do end up going with Rocky, there are a few mods that improve it. You'll find them all by searching for 'Rocky mod' here in the forums, but to summarize:
- plug screw holes in finger guard with foam ear plugs (or remove finger guard, if you trust yourself to keep your fingers out of there)
- teflon tape around burr threads
- mod for stepless
- I don't have a doser, but if you do, I think tape on the doser vanes so they sweep clean is a standard mod
- continuous grind mod, so you don't have to press the button the whole time
None of these are required to use Rocky, but they will improve results/ease of use, and with the exception of the last one, which requires a little competence with electrical wiring (and therefore, one I have yet to do

, they're all really simple too.