I can vouch for Mature Metal. The devices are top notch and it does mate perfectly with the DL2000. I will say that I had to order a new unit as retrofitting was not an option, but I was not in need to too much of a push to order a new one; the Queens Keep.
It has an insulating shield over the mounting pin that allows the ring to be isolated from the penis cage which in turn allows the entire device to be conductive.
I use it with the Mature Metal's custom sized Jail Bird which comes specifically adapted for the DreamLover. I find the whole metal entrapment to look more like a serious thing and less like a toy. It is very secure and comfortable as well and the DL itself does not add any discomfort.
Having said that, I still need to figure out a way to position the arousal inducer properly. So far what we do is to wrap it at the bottom of the penis with a transparent adhesive bandage, but I suspect that taping it to the bottom of the cage might work as we'll, just haven't tried yet. Also I find the standard length of the arousal inducer cord to be about 1-2cm short of ideal, and what I did do circumvent that was to open the receive device and pass the cord directly through the outside whole instead of around the main board . It puts some pressure on the cord as it needs to be bent in a sharp 90 degree angle but it was the only way to give myself an extra length.
Finally, using the Jail bird I always seem to fell the shocks at the bottom of the base ring, not on the penis or around the entire device as expected. I did nottice though that once when I touched the penis cage with my hands while being repeat shocked, I could feel the shock in my finger but somehow never in the penis. I don't know if someone else has had the same experience with the Jail Bird.
Anyway, the shocks on the base ring are felt strongly and as far as causing you to comply, they are pretty effective!