I was so tired of every article saying Windows Phone was dead and the phones that the NYPD bought were no longer able to upgrade. Both models can easily go to Windows 10 Mobile (or what ever MS wants to call it). While I do not think the decision to go with Windows Phone was a wise one, they have no reason for a complete rip and replace at this point in time. It can be done over time.

I haven't tried Deploy Studio, but I would agree that LANrev is very good. The support is amazing (maybe 2 hours to answer a forum question). Casper is also suppose to be nice, but when I was choosing, it was not very mature. Probably worth a look now though. That would cover your SMS style needs. You can also use it for some policy style actions. Other than that, you can join it to OS X or AD, so use what you have.