Thanks for the kind words about your existing PAR antennas.
The difference in the EFT-10/20/40 (Trail Friendly) and the EF-10/20/40 MKII is the the wire gauge used for the radiator, size of the match box used and a cosmetically different inductor in the radiator. The function and performance is the same. The Trail friendly is intended for more temporary use and employs the #22 wire instead of the #18. It is also much lighter. We recommend 25 feet of coax for the EndFedz since it uses the coax outer shield for a return path to ground.
The difference is negligible in the RG58 and RG174 for performance at that short of a run. ( less than 25 feet) Of course the RG174 is much lighter than the RG58. I believe Larry still offers the Teflon RG316 which is slightly larger than the 174 but not nearly as large as the 58.
Hope that helps you some. If not let us know.
73 for now,