I have a wireless router at present, an ASUS RT-AC88U, and a standard spark modem I guess. So, is it as simple as plugging in a new wireless modem to the phone lines? Why didnt they tell me that?
The FAQs section on the Spark website actually indicates that you can't liven up your phone jacks. My guess is that they take this position because, unlike a UFB install, they don't come to your house and disconnect the copper lead-in as standard. That would mean the sales reps are presumably trained to just say that it won't work. With your setup however, it should be very easy.
The specs for the modem they supply indicate it has a VOIP port, and the website states that you can plug in your own phone. My only thought was that the port might not supply enough power to ring several phones at once, but I can't see why that would be the case.