Actually, I wouldn't recommend ever maxing out a load on a breaker. Especially if you don't know what the condition of the breaker and/or wiring is. These lights take up a lot of energy, which will create a lot of heat, and if you're running things at a constant 100% you could find yourself starting a fire. 75-80% is the recommended max capacity.
200 amps x 120v = 24k watts, at 75% capacity that would be 18k watts you can safely run. However, you need to figure out what breakers are connected to what outlets in your house and go from there. I don't know if you're in a house or what, but with a 200a panel I'm going to guess a house in the suburbs for sake of example? Each room is likely connected to a 15A breaker, which would be able to handle a single 1k light or 2 600w lights and absolutely nothing else. Unless you've got yourself a kick ass central air conditioner and are willing to run it as long as you run your lights, you won't be able to control temps because you won't be able to plug in an A/C to whatever room your lights are in. No humidifiers, fans, etc, only the lights. The best thing you could do is do single 600w lights in each room as that would only be 5.3A on a 15A breaker, leaving you room for a humidifier/dehumidifier, fans, and an inline fan. This would still require you running central air so that's kind of meh too. There is no way you will be able to hook up an A/C of any sort on the same breaker as an HPS light, so unless you can light cool the light efficiently you could have some problems.
I recommend looking into a light controller for your dryer outlet, if you're not confident in your ability to do this then consult an electrician. It's a simple enough process if you know the basics. Just take a look at your dryer outlet, find the matching cable in as large of a length as you can and splice it into the light controller. I'm doing something similar with an RV hook up (30A @ 120v), I got myself a 25 ft RV cable, cut off the female end, stripped the wire and wired it into a 4 light controller. It's working out quite nicely for me and the same thing can be done with a dryer outlet instead. If you wired the light controller from the dryer outlet into one of the bedrooms, you could run 4 600w lights or 3 600w lights and a single 1k light on the controller, and still have the 15A breaker in the bedroom to work with. If you get your light cooling good enough to the point where your central A/C can help pick up the slack you'd be golden. Hell, if the 4 600 watters were light cooled enough then a 8k BTU window unit might even be able to do the job. It would only take 7-8 amps, leaving you with some wiggle room for your fans and a humidifier should you need one. If in doubt, consult an electrician!
If you post a few more details about the place you're working with I can do what I can to help, but unless you're confident in wiring a controller to a dryer cable or having single 600 watters in each bedroom with dialed in air cooling then you don't have many options without consulting an electrician.
Hope I was able to help.
