got rear ended - trying not to total - exhaust alternative to OEM?

[ol doc gully]

Hi guys,
I'm actually posting on behalf of my dad who has a 2001 boxster 2.7 (non-S), manual. He got a great deal on it with super low miles and has meticulously maintained it. Thing has never needed anything but oil and tires.

He got rear ended in a bad way. He's ok but the cost of repairs (by a dealership) is estimated at over $10k. State law mandates that anything over 75% of the value totals the car. Repairs include a transmission housing (only $933, presumably mount tab for exhaust?), $4,462 worth of exhaust parts, and the rear bumper - along with misc lights and fittings etc.

I am not there to take a look myself, but does it seem viable that there is no frame damage in this? I'm working on getting pictures from him. The 'transmission housing' makes me nervous along with a part listed as 'RT susp crossmember bracket' included with $933 transmission fix.

Assuming no frame damage, he would like to get it fixed as its worth more than $10k to him and he knows its well maintained and has anoethr 100,000+ miles in it easily. They want too much to buy back and try to get a salvage title not worth the hassle so we're either going to get a lower repair estimate or take the money and leave it.

he is currently trying to find another (non porsche dealership) shop for a quote. does anyone have a recommended shop in the huntsville alabama area?

TL;DR:
So in order to get repair costs down, exhaust seems like an easy target at $4462. it has one catalytic converter (99611302306) listed "LT" and one muffler and misc adapters, mounts, and supports.

How many cats are on these cars? looking at pictures there is one attached to header but i believe another before the muffler correct? because costs go up considerably if we're talking about replacing the headers, so would like to avoid. also due to the circumstances its not likely feasible to put an "offroad only" exhaust system on. do 'cat back' systems for these cars typically start after that header/cat pipe? is that likely what im needing here? i can give detail part numbers cited for repair if that would help

I'm largely looking at the PSE (but interested in any other recommendations - im sure he would prefer quiet), but honestly anything that doesnt sound terrible, wont flash codes and is in the realm of $2000 is a major win. Fabspeed keeps popping up more than anything, any comment on that system?

HUGE THANK YOU IN ADVANCE
(will get pictures ASAP)