Herewego, are you interested in non-USA PRC radios? If so, there are some significant reasons to consider them.
Your referral to the MX-6707 antenna, and other points you made, indicates you are thinking more about VHF than HF. Is that right? Then a VHF FM set may be to your liking (but that excludes HF and SSB). I know of no military radios that cover both below 30 MHz to give HF SSB. and above 30 MHz for 6 meter FM (and above) access (and that excludes SSB).
Some European countries used PRC VHF radios that cover several MHz below 30 MHz. Some have 25 kHz steps, too. That's important if you are planning on going into Ham Radio with your Technician license. Being able to tune below 30 MHz adds the 10 meter FM frequencies to your capabilities. 25 kHz steps allows you to tune to important band plan frequencies like 52.525 MHz which is the 6 meter National Simplex Calling frequency.
My recommendation would be German SEM-25 or SEM-35 transceivers if you want to drop down into 10 meters. They go down to 26 MHz. There are FM frequencies from 29.6 MHz up. The SEM radios do not offer 25 kHz steps though.
The British Clansman VHF radios like the PRC-351 are plentiful and cheap right now and do offer 25 kHz steps. They do not receive below 30 MHz so there's a trade-off, but they do have 25 kHz steps. The PRC-351 radios are tone squelch compatible with common US radios of that age. Our local Mil Veh group just bought some PRC-351's to communicate when we are in convoy (and they are getting their licenses!!!)
Or, you can stick with the US VHF radios like PRC-25, PRC-77, RT-524, or RT 246 which neither tune below 30 MHz nor offer 25 kHz steps, LOL. That does not mean these are useless, just that they don't fit into the 6 meter band-plan very well which limits general ham usage. You can still use them to talk to other hams on 6 meters if you coordinate frequencies, like the commonly used 51 MHz (which is not exactly band-plan compatible either).
Notice that there's no mention of 2 meters. These sets don't do 2 meters.
There's another way to approach this, too. Consider a PRC radio for HF operation. With a Technician license you can operate on 10 meters. You could use your MX-6707 which is made to cover down to 30 MHz and works ok down into 10 meters (28 MHz to 29.7). That would give you 10 meters USB. Most military HF radios are made for USB as used on 10 meters. Most also receive AM and USB for coverage of the CB frequencies, too. Obviously only receive would be legal.
Add an HF antenna and the world is yours. The cheaper HF radios I'm aware of being available are the Israeli PRC-174 which has USB and LSB, AM, and wide and narrow CW. Built in automatic antenna tuner also. Nice radio.
The British Clansman PRC-320 also covers 2 to 30 MHz continuously, has a built-in manual tuner, but has only USB normally. However, there are sellers who do a USB and LSB conversion to make the PRC-320 a very nice HF SSB radio.
Edit: You asked some specific questions I forgot to answer. No PRC VHF radio I know of can program repeater offsets. Distance coverage on 6 meters (where VHF mil radios cover) will be line-of-sight plus some. 6 meter signals do offer some terrain-following characteristics. Occasionally there are band openings on 6 meters and coverage can be hundreds of miles. The 6 meter band is nicknamed "The Magic Band" for that reason.
Good luck on your ham license!
Bob WB4ETT
