I'd be wary of plastic kegs. There have been multiple incidents of plastic kegs exploding at breweries in the last couple of years, including one incident resulting in a fatality. Many of the plastic kegs in the commercial market are intended for one use, to be recycled after that use. These kegs are not designed to go through multiple cleaning/filling/pressurizing steps.
From what I have heard, plastic kegs have a much lower max pressure than SS sankey or corny kegs, so extra precaution should be taken to ensure CO2 equipment is set up and working properly when using plastic kegs.