New exhaust, a few questions

[Rune]

Hey guys...finally got enough cash to do what I want to with my car. Its a '95 3.4L V6 with an ebay CAI. I've been playing on FTPP.com, and I think I've decided what I want to get. I'd like everyones opinion on what you think it'll sound like, what you would recommend, etc.

First, ceramic coated pacesetter headers. Part #PSE-1208C, 295$.

High flow cat. Since my catbacks going to be 3", I would need a 3" in, 3" out cat, right? What size would I need, would I need an air injector, 02 bung, etc? What does all of this mean? Regular oval, or short body? Thats between 60-80$

Flowmaster American Thunder Dual Split Rear Exit Aluminized Steel 3" Cat-Back. Part #FLOWMASTER-17143, 295$

Ebay rectangle Z28 tips (I don't know why, I just LOVE how these look).

How much would I shop charge to install all of this? How will it sound, and what type of gains would I expect? Does anyone have the same, or a similar setup and have any suggestions for me? Is there anything on my list that anyone would recommend against? Thanks in advance.

[FunkZ]

If you have a manual trans you will need to either modify the headers to accept the AIR injection, or leave the system disconnected. The Pacesetter Y-pipe collector is only 2.25" so you're also going to need an adapter or flare a pipe to get to 3". I was given a quote of $300 to install a set of headers. The same shop did my cat and cat-back for $80.

[Rune]

I do have a manual. What does the AIR injection do exactly, and what are the consequences of going without it? 300$ is incredibly steep for a header install, I can do that myself. Would the Y pipe bolt right up to the stock exhaust long/well enough for me to take it to an exhaust shop and install the rest?

[grayman]

Um, I don't think you can flare 2.25 out to 3.0.
typicaly it is no more than 1 to 2 1/4 size increase for flareing pipe. It just cant stretch that much. What other Clear image header people doing?

On my magnaflow LT1 v8 cat back I ordered a 3/3 cat with rear o2 bung. stock v6 system has o2 bung in s pipe. I did it this way so I would not have to take the s pipe in to muffler shop to have o2 boss welded in. this setup works great. no codes.
I have no help for air tube deal. auto trans here. they do make CATs with air tube though. (?) if that is any help.

[FunkZ]

The AIR injection system on the 3.4 and LT1 uses an electric air pump to pull clean air from the intake and force it into the exhaust manifolds. Some cars put the air into the converter, but on the 3.4 it's on the passenger-side manifold behind the EGR. Only the manual trans cars had this. You can disconnect the system, it may set an SES code, and it's certainly not legal in any state that requires emissions tests. Check your local laws before doing this. It should be fairly easy to have a bung welded on the header to reconnect the system.