The 2GIG SMKT8-345 smoke detector would be compatible with the 2GIG Go!Control and is the newest smoke offering from 2GIG.
I have a ct-100 thermostat, along with 4 wireless sensors I’d like to bring over.
Note that the CT-100 thermostat is no longer supported by Alarm.com on new accounts and could not be used to remotely control hvac or set up automation rules/schedules. More information on that can be found here.
Any 345Mhz sensors currently enrolled in your panel should be fine.
Would I be better suited at this point to upgrade the communication module, firmware and buy a new smoke or do some sort of bundle upgrade to a new panel?
You could do either, both would be perfectly viable options. Once the firmware is upgraded and the new 4G LTE module installed, the 2GIG Go!Control would be compatible with service.
As for a new panel, we recommend the Qolsys brand IQ Panel 2+ as it offers a 4G LTE cellular module, built in wi-fi, compatibility with DSC PowerG encrypted sensors.
We offer the Qolsys IQ Panel 2+ with 345MHz radio, found through this link. It includes a radio for PowerG sensors and for 345MHz sensors (for compatibility with 2GIG and Honeywell 345MHz)