Extra 15 feet of 1/8 OD plastic hose (if you kink the hose, you're done)
Extra 1/8 compression fittings - Male and Female. Maybe two each
Unions
1/8 Bushings (easy to drop and you will never find it, or at least until you are done and it will be sitting on your fuel filter lid

)
1/4 to 1/8 reducers
1/8 90* elbow
3/4 to 1/8 galvanized reducer (if your boost gauge does not come with a boost bolt. The alternative is to drill and tap the intake horn)
1/2 drive ratchet (to remove the plug for the 3/4 reducer - between the MAP sensor and the fuel filter)
Grease gun hose with 1/8 NPT threads (Fuel pressure gauge)
Needle valve (together with the grease gun hose to make an isolator - takes the pulsing out of the pressure, and makes a handy shut off if you spring a leak)
Drilled and tapped banjo bolt (I had to use that for my fuel pressure gauge)
7/16 drill bit (for 1/4 NPT EGT hole)
1/4 NPT tap
I can't remember the drill size for a 1/8 NPT hole
1/8 NPT tap (probably won't need it, but you might)
3/16 to 1/4 ID vacuum hose (to protect the boost, and pressure hose in areas that they may be rubbing.
A can of grease (for drilling and tapping - catches the shavings when you coat the threads of the drill/tap)
I have no idea what you will need tor the transmission temp gauge.
Electrical spade connectors and 18 ga wire.
You probably will not need all of the above, but it is sure nice not having to say "CRAP!" then waste an hour driving around looking for parts.
When you get everything in, take a look at all the parts and figure out how and where they will all go before you start or even go shopping. You will know exactly what you need, and take the parts with you to make sure you get the right stuff.
EDIT - Oh yeah, READ THE INSTRUCTIONS FIRST! If the gauges do not come with them (mine didn't) do a search and get some! Saves a lot of brain dammage.