Well if you want to go boosted in the future, UDPs won't be any use because you'll need the stock pullies to run one.
CAI, realistically a K&N drop in filter in the factory airbox will get you where you need until you need to make big power. If you go centrifugal the piping is going to replace the CAI anyway, if that's the route you choose no sense in wasting money on a CAI.
TB/Plenum is helpful, and the gains are even more once you supercharge. Obviously if you go with a positive displacement blower the plenum will be useless as you won't be using it.
If you just want a good all around cam that will work both n/a and boosted, the stock PI cams will suffice and you can get them dirt cheap. The aftermarket cams for NPI heads really aren't that much better powerwise, most of them are pretty similar to the PI cam specs aside from a slightly tighter lobe separation. Either way you go, you're better off getting custom grinds than off the shelf grinds, and they don't cost any more anyway. Tim at MPH can hook you up with some for the same price you'd be paying for comps, etc anyway and they'll make more power than an off the shelf grind.
Stock PI castings plus boost will make more power than the stock rods will handle. If you don't plan on going with a forged block, really the simplest setup would be a full PI engine swap which you can easily find in the $1000 range with relatively low mileage. Newer engine, no issues with compression increase, great drivability.
The main thing is to consider what direction you plan to head in the future.
If you go with something like an S trim or Kenne Bell 2.1, stock PI heads, built bottom end, custom blower cams, supporting mods (plenum/tb, fuel system upgrades, CAI if applicable, few other odds and ends) will be all you need to get all you can out of them. No sense in porting heads or going crazy because you'll max out the blowers before you'll max out what the engine can handle on pump gas. On both of them the supercharger itself becomes the restriction at those power levels as you've basically maxxed them out, porting heads etc will most likely hurt drivability more than help it. By the time you get to those power levels you're going to need to upgrade the fuel system anyway.
If you just want to go as fast as you can go on a $1500 budget, get a PI intake, PI cams, a shot of nitrous, and gears. Nothing is going to get a stock-ish NPI GT faster than that on that kind of budget unless you find a really good deal on PI heads as well, if so add those to the list.