In that case I'd stick w/ the stock 606's. Or get some NGK TR-55 V-power plugs. Those also will work. Been running them in my 95 Bonneville and my 00GT for a while now and no issues. I just check them when I change the oil for gap and off I go.
Def. stick w/ the stock Delco wires. And no, you don't need to change the coil packs to MSD. In fact they have been known to suck. Stock packs are more than enough for most of the cars here (even the heavily modded ones).
For your tune-up I would also clean the MAF w/ approved MAF cleaner and change the fuel filter as well. Don't forget to check the air filter too.
Some additional food for thought- When you change the LIM gaskets are you going to refill w/ the Dexcool, or change the system over to the normal green coolant? Your call there. If you decide to change to green then you MUST flush the entire system to remove the Dex before you fill w/ green. Dex and any other coolant type do not mix and you will have issues as some point if you try this.
While you're doing the LIM gaskets you may as well replace the valve cover gaskets and grommets as well since I'm sure the front one is leaking by now. Probabaly dripping onto the front manifold.
Besides the LIM gaskets themselves (make sure you get the alum. ones), you will need new injector o-rings for all 6 injectors, new UIM gasket, 2 new coolant elbows (yours will break when removing the tensioner assembly), some gray RTV for the 4 corners of the LIM gaskets, brake cleaner to clean the LIM and head/block surfaces before reassembly, some towels to plug the intake runners while the LIM is off (trust me, just do it), and enough cheap oil and a filter to fill the car and have 1 quart to wash the lifter valley out.
This is just part of it, there is more in the writeups on here. Just trying to cover some of the basics.
