The problem with the LPG in some parts of the world (and Oz) is that it has a high percentage of nButanes and other heavies in it, which drastically lowers its vapor pressure in cold weather.
I had a mate in Oz who put together a very nice Prins system on his turbocharged car c/w dual injectors, only to find out he didn't have enough gas pressure to run it.
Here's a cut & paste from an email he sent me when he made the unfortunate discovery:
"Well the news with the injection is not good. I was worried about the pressure the tank would drop to in our cold ass winters. So I have a 4.5kg bbq cylinder that I filled from the cars LPG tank. First off I tested the pressure at 35 degC = 85psi. Yup, this is pretty low huh. Lower temps did not bode well for it. Then I popped it in the fridge to lower the tank to about 4degC. Now this one is the eye opener......28psi!!! Now considering that when on boost I will be running a rail pressure of 45psi....yep, Houston, we got a problem."
He wound up "liquidating" his whole Prins setup on eBay for a fraction of what he had in it, then put on an ancient "suck through" Impco setup, then finally sold the car.
Ed, I can probably put you in touch with my friend, if you're interested in emailing him about the problems he had? PM me your email address if you're interested, and I'll try contacting him for you.