It sounds like you have gotten good advice from your County Sheriff!
The programming is the same on all of the DTR models, except the DTR410 radios can be programmed using free software from Motorola. The others require more expensive software …
… BUT you should consider exactly how much “programming” you need to do. For basic channel and public group programming, it is all done through the radio keyboard. These are very sophisticated radios, but they don’t have to be complicated if you don’t want. Unpack them, turn them on, maybe change the channel and unit ID to a different number than the factory default and you are good to go.
The software is only needed if you want to name all your radios and your groups with unique alphanumeric names, instead of just the default numeric names.
Quite frankly, I wouldn’t bother. Just unpack them, turn them on and you are ready to go.
If someone gets real ambitious, you can buy the Motorola mini-keyboard and program each radio one at a time, but again for most people, they can just unpack them, switch the channels to match each other and just start using them. You do not NEED any “programming” to use them right from the box.
If I may be so bold as to offer a recommendation based on my testing, I think the DTR radios would work perfectly, and you won’t need the DTR550/650; the DTR410 will do everything you need.
Yes, they are expensive but they are an industrial-grade business radio after all. The first time you take your FRS radios out in the pouring rain, you will regret not getting the Motorola DTR radios!
The 900 MHz frequency band also does a great job cutting through the metal and concrete of buildings in urban areas that VHF radios may struggle with a bit more. As for range, no VHF or UHF (the DTR radios are in the high end of the UHF frequency spectrum) radio is going to give you more than a few blocks under ideal conditions but my exhaustive testing has shown that the DTR radios have about as good a range as it is possible to get with any portable VHF/UHF radio.
The other thing is that the DTR radios are pure digital, meaning that the broadcast always comes across crystal-clear. And I mean CLEAR. The readability of the voices is one of the best I have ever heard, and they are so clear that you will cry if you had to go back to an FRS radio.
Because the DTR radios are digital and they ‘hop’ frequencies every 90 milliseconds, they cannot be monitored by consumer-level scanners. Only Motorola DTR radios can hear other DTR users, and if by some very very rare chance there is another person outside your group with a DTR on the same channel and same unit ID number (there are 10 channels and a 100 unit ID numbers available) then you can easily switch channels. You can also program each radio’s unique identifier into each of your other radios and set up your own virtual private “net.” Each radio can be set up to broadcast ONLY to other users programmed into this private “net” (private one-to-many calling.) You can also call one other radio at a time (one-to-one calling) almost like a cell phone, and other users can use the same channel as you at the same time.
Another issue is the legality. I know some schools use FRS radios for your purpose but this is not legal because the FRS band is designed for recreational use among family members. The DTR radios (and the TriSquare radios) transmit around 900 MHZ and not only do they not need any kind of licence but they are also totally legal for personal or business use.
There are some downsides. Unlike the TriSquare models, the Motorola radios are pure digital. This means they either work 100% or they don’t work at all. Before they transmit, they will send a 1/2 second ‘handshake’ signal to other radios on the same channel and unit ID number to be sure at least one other radio is within range. If there are no other radios within range, they don’t transmit at all. There is no fuzzy signal at the very edge of their range; they are 100% clear or they don’t transmit at all. FRS radios are plagued by interference from hundreds of users all fighting for the same few frequencies and you can sometimes get a lot of interference.
The other downside is that you need to educate users a bit before they use it. You need to show them how they have to hold down the push-to-talk (PTT) button, listen for the 1/2 second tone, and then start talking while holding down the PTT button. They should also hold it down for another 1/2 second when they are finished talking, just to be sure they don’t cut themselves off.
When I give new users my DTR radios, they almost invariably forget to wait for the 1/2 second ‘handshake’ tone before they start talking, or they push down on the PTT and hear the tone, release the button and start talking. It takes a bit of edumacating users.
As for the 410 versus the 550/650, the 410 has a shorter moulded-in antenna that is only very slightly shorter range than the 550/650 with their longer ‘rubber ducky’ antennas, but the generation II DTR410 has some great features that even the 550 doesn’t have. Our hosts on this forum sell the newest generation 410 (and I am sure they could special order the 550 for you if you wanted) but quite frankly, for the purposes that you describe, the DTR410 is going to work perfectly.
I will absolutely guarantee that if the cost is within your budget, you are not going to regret spending the money.
I hope this helps. If you have any more questions, please feel free to ask away. I have several DTR550s and a DTR410, and am starting to know these radios fairly well. They impress me more and more every day. (Now if I could just get people to remember to push the button, wait for the tone, and THEN start talking …)