I did them on my 97 I did it on a budget, no stage 8's those bolts they provide are cheap but they work just put high temp thread locker on the bolts otherwise when they back out you'll burn a gasket, you don't have to get new 02's, get a pair of extension's for the set closest to the motor I would hold off on the pcm tune drive it and see what you think. I did it with floor jack's and jack stand's, defenitely have to take the pass side motor mount bolt out and jack up the engine and make a lil' extra space in there I would do the drivers also .I went down to mineke and sort of help'd them and they only charged me 60 buck's to make my y-pipe it's 3" all the way so it sacrifices a lil' ground clearence so you'll have to slow down over speed bumps and such . I got the LT4 KM but I won't swear by it just yet, and it would probably make alotta sense to just have your friend do your wires while everything's apart unless you have some time andlike everyone else said patience. And 02 SIMS if course if that's the route you want to take It's probably safer to keep the 02'S

 

You could get by with not getting all these parts but i like to do my stuff right the first time. LOL i say that and i'm pulling my TA door panels out and putting in different ones right now. Here is what i would get
1. Over the V/C wire looms
2. MSD super conductor wires, I think taylors are junk.
3. A good set of header gaskets, I'm running Mr. Gasket ultra seals. I've run copper and they were fine until the bolts backed off once they started leaking i could never get them to stop. I also used some Percy Dead soft Aluminum header gaskets, they leaked too but some of that might of been they were blocking the ports on my ported heads, which may of helped them leak. I would just get some good "Paper" gaskets IMO.
4. Just get some 3/4 inch header bolts from your local parts store and put antiseize on them. Get 1inch bolts if you have thick metal header gaskets, like Percy gaskets. I've had stage 8's and i think they are junk. The allen head tries to round out and so does the head. i think they are made of soft, junk metal, they also don't work that great either. If you want something really special get the Breslins.
5. You'll need 2, O2 extenders.
6. You'll need 2, O2 sims or OBD1 conversion. I would go with the OBD1 setup if you don't have emissions.
7. New plugs, i run AC delco's they are damn good plugs and are suppose to be good for 100k, although i won't run them anywhere near that long.
8. LT4 km, they are good to have and do help. I've seen differences on scanners. Saying that headers are louder isn't really true, they usually don't make the car any louder, its that most people ditch the cat when they do headers and that is what makes it loud.
9. I would probably run Percy's Aluminum collector gaskets.

Do as you wish but these are the parts i would get at the least. I would ask your buddy if you help if he will do it for $150 that way you learn something and get some help.