The major problem I was having is resolved. I've finally got a UHF backyard pair for my portable repeater :-) No more hassling with trying to pack 4 radios into 1mhz of VHF bandwidth :-)
Since there isn't a way to look at receiver specs and figure how much isolation is really needed, here I am asking - what is my best bet for radios to build a UHF repeater? I'm currently looking at a Hamtronics receiver/exciter pair with separate PA, but I'm pretty much open to anything I can get at a reasonable price (300-400 for both RX and TX, PA extra if needed). The repeater controller I will be using has PL built in, so the radios don't need it. I would prefer 50 watts or better output, 100w max. Size is important. I've only got about 16" of depth to mount this in, though there is a way I can get bigger than that if absolutely necessary. If the equipment recommended has any "front panel" controls, it needs to be 16" or less front to back. If no controls, then I have a lot more freedom in mounting.