My recommendations for intake/exhaust:
K+N as mentioned with a maf adaptor and heatshield is imo the best. I'd get a y-pipe (shoshop, brullen or trubendz) and a quiet exhaust like borla, resonated trubendz, or brullen "quite." This will give you some extra power and not be anoying for everyday driving.
Definately get a dmd, because it only takes 20 minutes to install, costs around $50, and increases engine longevity. You already know about the waterpump.
As far as the rest, get what you want. I find the best aesthetic mods are pretty cheap. "Knauberizing" is free, pre-98 sails are cheap (I traded straight accross for mine), I just painted my front chrome ring for 10.00 in paint/primer and will paint the rear chrome strip soon, ect...
