My main concern is flash effectiveness, how close do I have to be or how powerful a flash does it have to be. Is the combination of flash and focal length of the lens or just being in the effective distance of the flash more critical? I do have access to a large combination of equipment (my buddies are photog nuts too).

Shoot from the floor -- at the corners or under the basket (outside the court obviously). Leave your zooms at home. A fast fixed focal length lens is what you want -- both for speed and for simplicity's sake. An 85mm is just about ideal. A longer lens, such as a 180mm will work well for down court shots but the 85mm is your bread and butter basketball lens. As for exposure, the most important thing is shutter speed. You'll need 1/250 minimum to effectively stop action. That means pushing film or buying one of the high-speed films. Usually most high school gyms are bright enough to shoot 1/250 at f 2.8 at 1,600 ISO. That is generally considered the minimum light level and about all you can expect from most non-college arenas. If your gym is quite a bit dimmer, try shooting from the side and panning as your son moves down the court. If you're going to attempt flash, again shutter speed is important. Ideally, you'll want to shoot at 1/250 if your camera will synch that high. Try to use as little flash as possible. Set your auto mode at 2.8 or faster if possible. If you've got a fairly modern camera with TTL flash metering you might try adding flash to the basic 1/250 -- f 2.8 -- 1,600 ISO equation so the flash is just kicking out a blip to fill in the shadows. Shoot lots and expect little. If you shoot four or five rolls and get four or five really good shots you've done good.