No, you have a late 99. 12/08 is early/late.
You should get:
Intake - Can be done for 50-75ish depending on well you do it
Exhaust - You can always just get a cheap delete pipe but full systems maybe 350-450
Gauges - You can go cheap, or get an Edge all in one, or just the common three for 350 maybe.
Custom tunes for sure. Tony Wildman, PHP, Beans, Swamps, Gearhead, Innovative, Tyrant. - TW with chip and 6 tunes is 425 I think.
Valve body for an auto trans to help it hold the extra power - Got one for 125 barely used. New maybe 175.
6.0 trans cooler would be a good idea - All kinds of prices. New is 300ish cause of the demand.
Possibly a larger turbo for bigger sticks. Not sure at what size you need to upgrade. - 1250 minimum
Possibly a larger HPOP for reasons above. - 500 ish and up.
I'd at least do a a FRx, if not a full RR fuel system. - FRx is in the 150 range. RR can be done for a few hundred all DIY or more if you buy it.
What size injectors?
This is from Casserly's site - Stage 2 Single Shot
New Stage 2 Injectors will flow the same 160cc's of fuel the Stage 1 injectors do, but utilize larger nozzles. 400-425+hp is obtainable with a custom chip, upgraded turbo, and fuel system. That will be 140hp above stock horsepower with supporting modifications. $2299 + $1200 Core.
Rosewood - Budget Stage-2/s: $885 Overhaul, retains AB or AD fuel output, new nozzles flow 80% over stock. With correct supporting mods, these are capable of around 350 - 375 hp.
Premium Stage-2/s: $1235 Overhaul, retains AB/AD, new Plunger & Barrel assemblies, new 80% over Nozzles.
Premium Stage-2/c: $1335 *Overhaul, converts to 160 cc Single Shots, nozzles flow 80% over stock. With correct supporting mods, these are capable of around 400 hp.
Swamps - http://www.swampsdiesel.com/prestashop/en/76-1999-2003