Natural Gas or Propane CO2 generator?

Last I'd heard there was no choice, gas wasn't an option. Then I'm shopping for a propane unit and I find this one with natural gas or propane versions.
http://www.gchydro.com/CO2+Generator.html


So, there is a gas one, cooool. Anyone use this one or any other natural gas one and have anything to say about one over the other?

Aside from the expense of installation I think I do want the gas one so I never have to lug tanks around with my bad back.

But then again, how the hell am I supposed to get a guy out here to work on the gas line and hook that up without him knowing, it's not possible is it? Is there a way to have them run a tap and not hook it up to anything or have them hook it up to some bullshit thing I take out when he leaves?

I'm willing to do a lot of work myself but screwing with the main gas line is not on that list.

I feel the same way as you about things (and I realize that this is an old thread, but you might still be interested), but if you've changed your mind, check out this link:

https://www.rollitup.org/grow-room-design-setup/273330-natural-gas-lines.html