Is there any official or third party cellular dialer/network backup I can plug directly in the smarththings hub or otherwise to keep a connection on it as I use it for my alarm system and all someone would need to do it cut my cable connection which would kill my internet to my router which is is currently connected on? I have battery backup UPS system it is plugged into and I think it has batteries of its own but what about internet backup for it.
Not as direct attached to the hub, no.
You can however get quite a few routers which have cellular cards/USB attachments. You will also need to make sure that both devices are on a UPS too (and any switching equipment in the middle).