Do you need the talonfx controller for swerve?
As your question is worded: No you do not. E.g. you could be in the rev ecosystem.
However, to give a better answer, a rundown of the other hardware you have/are considering can help us give you more advice and link resources.
I was trying to make sure if we would need this we order it as soon as possible. What else could substitute it or is it completely optional to have?
If you are using a kraken or a falcon 500, they have built in motor controllers.
if you are using something like neos then you need a sparkmax or the neo vortex motor controller.
If you could tell us which modules (SDS, Rev, WCP, TTB, etc) you are/plan to use and crucially what motors you are planning on using for steering and for drive.
Then we can help better.
In general, see @10219Ryba 's post above
We are using swerve x flipped kraken for steering and rotation
Hopefully this helps
Krakens have the controller included on the back of the motor, so good to go for these motors!
Okay thanks
For swerve you generally need 4 Drive motors w/ controllers (Falcon 500, Kraken x60, Neo W/Sparkmax or Neo Vortex w/ Sparkflex), 4 Steering motors w/ controllers (Falcon 500, Kraken x60, Kraken x44, Minion w/TalonFXS, Neo W/Sparkmax, Neo Vortex w/ Sparkflex or Neo 550 w/ Sprakmax), 4 absolute encoders (CanCoders, Canandcoders, throughbore, etc.) , and a gyro(NavX, Navx2, Pidgeon, Etc…)
(Just adding to the short list: more wiring and your preferred connector / soldering than you may think)
So much wiring!