Correct, I have a set of VHF duplexers down in storage, they are tunable so you can set them for your pairs.
Cap Kilo is also correct about :
If you re-read the link you posted there is this:
You have a radio(s) that is listening at the same time it is transmitting, and life will suck big-time if the front end of the RX is being wiped out.
We encountered that with the machine we set up for the club.
and there is another reason to reduce power out put, not only to increase duty cycle of the radio, but the more RF you are stuffing up the coax while the RX is coming down, the more you will fight desense.
There are also plans on the internet, if you look, for building a 6 cavity set out of Copper tubing ( read BIG copper tubing ) but at the price of copper today that will add up quick.
I will find it and post it in a little while here.
73
Jeff