Muscledriver has some great deals on bumpers, but since you live in Long Island, you might want to buy from Werksan, drive down to Moorestown to pick the stuff up, and take an Olympic lifting workout or two down at the trianing center in Moorestown. It gives you an excuse to come down there. I suggest going on a Saturday, since many lifters form all over the area often go there on Saturdays. if you let me know when you're going, I'll try to come up with friend or two. You can also try out the equipment there- they have samson bars, york bars, elieko bars, and werksan bars there.
As for bumpers, and for starting a facility, go for the 10s and 15s in composite bumpers. You can get 2x as many for the same price, and if the bar is being used with only a single pair 10s or 15s on it, the wider bumpers will help absorb some impact on the bar; if you want to use bumpers on an axle, the composite bumpers will fit better on most axles than will the truer expensive bumpers (the ends of many axles are 2 inches; the certified and trianing bumpers are 1.97 inches, and it does make a difference). Get nicer 20s and 25s. I think the Werksan black training set is nice (under their training sets, not composite/ rubber). I have those same plates and they've held up for years.
For kbs, try to avoid the shipping hell. If you buy in bulk from, say, Power Systems or someone, ask for a quote. I had a quote a few years ago that would have saved me $300, but I bought other stuff instead.
Bars do make a difference; I'd go for the nicest bar you can get. The Pendlay HD bars I've never tried out, but I have used the older Pendlays, and they're fine. Not as nice as Werksan or Eleiko, but you can get two for the price of 1.
Older York bars are great; their elite bars from the late 90s are some of the best value you can get if you can find one used. Not many people are selling them, though.
The Samson bars Werksan has are nice, too. I really dig them. Again, as far as value goes, two for the price of one nicer bar.