@Junior, I'm still learning about DCC and o scale and will answer as best I can.
DCC is a standard maintained by the NMRA, it is the command system in all the other scales, from Z to G. The decoders made for G scale will also work for O scale. 2 rail O scale has been using DCC for years, not really new as such. Yes, you will need another command system, DCC is not compatible with DCS/TMCC. I use a DPDT switch to select either DCC or DCS/TMCC to the rails on my layout. There are many manufacturers out there, I use the Digitrax 8 amp starter set and a $30 180 watt DC power supply from Amazon. The best part is everybody's decoders will work with any of the DCC command systems on the market. One remote to run them all!
If you don't want to buy another system, Soundtrax should be releasing the 4 amp Blunami this year. This is the same as the Tsunami2 boards I use plus Bluetooth, runs with an app on the iphone, not sure if they will work on AC power, will probably need DC power or add a rectifier to the loco. Or go dead rail, there are folks here that are doing that.
I have so far converted a RMT Bang and a MTH PS-1 loco to DCC, all you need is a loco with DC can style motors. I have seen where universal motors were made to work on DC power but I think it is easier to send the loco to Frank Timko and have can motors installed. AC only motors will not work and would have to be replaced.
But, yes, we have choices other than MTH or Lionel for command systems.