Replacement Plug at rear of (Keg King) Kegerator

[Woldie]

My Google Fu seems weak - I cannot find a search term that yields any results.

I am trying to adapt my Keg King 4 so that it can accommodate two different beers at two different pressures, but I cannot for the life of me find replacement plugs for the gas line exit at the rear of the fridge. Any recommendations? Thanks!

[djc]

I assume you currently have one tank outside? Why not keep it that way and use a dual regulator set up inside?