I take it that this is a 5-speed Integra.
The first step I would take would be proper maintenance. Make sure everything is in ship shape before adding anything to it. You'd be surprised how much you can get back just doing a good fluids change and tune up. But yeah, a good maintenance weekend would be the first step. Since these cars are getting old, I wouldn't take the previous owner's word on if the timing belt and water pump was replaced or not (unless you were provided paper evidence).
So, basically I would probably start off with a 90k service w/ belts and water pump. On the timing belt, I would suggest sticking with Honda or Bando belts. Water pump, I like the Honda pumps for longevity, but something like an Aisin (OE manufacture) or GMB is fine (these tend to have on average of about 10-20k mile shorter lifespan). The standard plugs are NGK V-Power copper plugs. You can upgrade to something like the NGK Iridium IX if you'd like for a better spark. Plug wires, I tend to stick with just your standard NGK wires. I've thrown a lot of voltage through standard NGK wires before and they've held up quite well. Distributor rotor, stick with the Honda as many aftermarket companies try and make a "multi-fit" rotor. They don't work worth jack shit. A standard cap should work just fine. Getting a valve cover gasket set (w/ valve cover grommets) will be handy, and do a valve lash adjustment. Other then that, a fresh fuel filter is cheap insurance. That should cover the bases on maintenance for at least a good 80k miles.
Things I would change out would be that interfooler intake. They don't work that well being that they're placed in a high pressure area (you get lots of air turbulence in the intake tube, which doesn't help you make power). Also, with a older car, upgrading your cooling system wouldn't be a bad move to do either, especially if you live in a hot area like the southwest. But as far as mods go, it really depends on what you're looking to do and for what purpose. So, some more information would be welcomed.
Also, just FYI, I've been a long time dealer for many of the top brands in the industry, and I still sell these parts. You're welcome to pick my brain for knowledge, I just ask that you give me the opportunity to serve you with the parts that you want.
