is the general consensus that triggering a plugin like SD3 or SSD from e-drums the best way to go?
I personally hate the Roland drum sounds and would rather spend more money to get the best possible sound!
It will provide the best possible sound quality IF that library does provide the sound that you are looking for. However you need a quality Notebook + Interface and have more possibilities of failure in a live situation.
The alternative would be to get rid of the TD-25 module and replace it with a used 2BOX module. You should have some coin left this way for your monitoring solution. I have all the sounds from all Superior and EZDrummer Expansions, BDF, Slate and other samplers converted and ready to use, probably like 250 high quality snare drums, most of them with over 40 velocity layers, while most Roland modules only have 3 or 4 velocity layers.