V8 with catalytic converters & gas

[Rodrunner]

Hi Folks, I have a question about V8 and conversion to LPG gas. In Germany there are now so-called environmental zones. There only are allowed to drive vehicles with catalytic converters. Are there conversion kits for fuel injection systems with catalytic converters?
I work at a car dealership has its own gas filling station there I could refuel.
Has anyone of you experience with conversion to gas? Are there any alternative?
Which engines (Ford, Chevy) are particularly well?

[Weasel Diesel]

I dated a gal in high school that her parents had made the conversion on a 78 malibu w/350. Ran darn good. here's a link that may provide some more help

http://www.hendrixsystems.com/

[Rodrunner]

The conversion to gas is not the problem, our company also makes such conversions. I would just like to know whether there are experiences to old engines. Perhaps i would buy a 350 engine with 350 transmission if it's possible to buy a fuel injection systems with catalytic converters for this engine.