Gonna swap original out of a 02 maxima with a 09 maxima(VQ35 but with an HR head). Woundering if I can fit the cat trans in it to??

Even if it were possible, why would you downgrade the transmission? It's already near death. CVT is garbage. Where have you been?

what’s the best option

For auto transmissions the one you have is basically all there is. You can upgrade the valve body on it to make it more “performance” orientated but as far as the trans itself youre stuck with what you got.

my suggestion is to put in a 6speed and learn to drive manual, it only seems hard because you never tried it yet. I promise you its not, plus your car will be much more enjoyable to drive. With the 6speeds you can also find one that is HLSD which is great for snow covered roads and putting down power from a standstill.