Exhaust system & components

[Krem]

ok, so I'm a bit nervous. I'm building up the funds to get the parts I need... whether I'll be able to put them on myself or have to pay someone else is a fork in the road to arrive at later. Even if I have someone else do the labor, I still like to provide all the necessary parts to ensure 1) all parts are onsite and ready to go, no waiting three days for a part to arrive; and 2) ensure I'm not getting overcharged for OEM crap (possible refurb at that) that their supplier provides.

I think my headers are jacked, I'm hoping it's the cat that needs to be replaced (else I am at a loss for the cause of my present issue), and I figured if I'm doing the front half of the exhaust system, I might as well put on a pipe and muffler tip.

Anywho, here's the real questions:
1) Looking around at all these parts, I see our supra has a wide variety of part numbers on the catalytic converters... what's the difference in the parts vs different numbers? Personally, I'm looking at getting this cat as it looks similar to what I already have and matches the 2.5" that I want to achieve. Will this part be suffice? or would there be extra work in getting it to work with the mkIII?

2) I seem to see soo many different pipes for the exhaust and I'm not sure what's what. I'm looking at getting this header set. With exception of the manifold bolts, since it comes w/ a gasket, does that include all I need to go from exhaust manifold gasket back to the cat? or is there something more I need?

3) People often talk about catalytic converter repairs as nightmares. Even heard a guy say he'll toss his car if the engine, tranny or cat dies on it as the repairs become more costly than the car itself. However, looking at our car, it looks like the cat would just drop down and should make replacing quite simple? Am I wrong in my assumptions? or did we luck out with an easy to replace cat?

4) After the cat, I need to know what I need between the cat and the muffler tip. Is this considered the down pipe? exhaust pipe? and what components are involved? (I will likely have an exhaust shop make me a pipe to connect from cat to tip, if possible, I just want to know what all should be there)

5) Finally onto the tip. If I go 2.5" all the way through the system, should I stick with a 2.5" inlet? or would I be able to get away with a 2.4" inlet? That would make the difference between getting a generic tip vs a decent tip


Also any other advice or recommendations is always welcome. My biggest worry is that, short of the o2 sensor, I might miss or over look some aspect or part of the exhaust system that might cause me headaches when it comes time for the install. Thanks for makin it through my thread, and preemptive thanks for answer any of the questions above.