Brand Noob Exhaust Blowout

Greetings fellow Nissan 240 enthusiests,

I drive a 91' 240SE with about 85k and I'm a brand noob to this site...

I have a little delema, my rusty stock muffler tail pipe has blow out from my rusty catalytic converter. I'm looking for a cost/preformance efficient replacement. I'm looking towards a test pipe and a stock exhaust. Problem is that I'm running a stock KA and i'm worried about back-pressure issues. I live out in Podunk so i dont have to worry about emmission laws. I know that if i open my exhaust up too much, i'll loose torque and i'm not even sure if i'll gain any power. Test pipes up here are about $30-$50 and cats are about $100-$200.

If i go with the test pipe+stock exhaust replacement, do i have any mechanical problems to worry about? Should i even cut the cat out, or should i just replace it with a new cat and new stock exhaust?
I'm in the process of building up my car to be a drift/autocross-worthy daily driver. I'm more interested in preformance and durability than i am sound and looks. I really dont want to sound like an angry bee, buzzing and vibrating down the road unless the fuel mileage and preformance is better. I'd rather sound like a deep bellowing sleeper :)

I know NAs need a certain amount of backpressure to preform properly, and from the factory the KA24DEs are bottled up and rev crappy.
I know free flowing test pipe cats and open exhausts are designed for turbos, and so far everyone i've talked to has been about 50/50 split on the subject, but would it be ideal to go test pipe or should i just replace the stock parts with stock parts? I'm on a bit of a budget considering i'm saving up for suspension parts.

So....

Basically to sum up this post, can anyone help me out with deciding what to do, give me some pros/cons and info regarding this subject?

I'm willing to bet that this same question has been asked many times before, but please I beg you for information because i'm torn and at a loss... :confused:

Thanks in advance,

AJB

Some people have said to have gained horsepower even with a cat-less 4" on a stock KA. Whether that's true or not, I don't know. I do know that you won't lose any torque with a 3 incher and cat, I dunno about 3" with test pipe.