Is a catback exhaust system a combination mix of a catalytic converter and muffler, or is it the pipes and muffler that is behind the catalytic converter?

I have just installed a set of SLP coated headers on my TA and have ordered a Dynomax catalytic converter. My exhaust pipe that leads from the output of the Cat to the input of the stock muffler is 3 inches. Can I now purchase a good quality muffler and will that make a catback exhaust system?

Thanks,

 

Sorry it's 240 am and I'm drunk as ehlls but a cgtack , is everything after the cat back. soryy if i've missed a wquestion but i;ll catch it in the mroning, lmao.

 

OK, i'm better now . A cat-back is the intermediate pipe that is after the cat.

Now, since you already have a 3'' pipe, just get any muffler that you would like.