Yeah, that sounds like a great set up. I have a separate room for vegetation at my place as well. It's really nice to be able to get your next plants going while you're flowering. I take clones right before I flower, so that I have 2 month old bushes ready to flower by the time the current crop finishes. The plants get up to about 4 or 5 feet in that time, and I just veg them under CFLs at first, and then move them under a T5. The T5 is so cool that all I need in my veg room is a box fan and an outlet fan. I spent all of $16 on cooling that room, and probably $200 to light it. Cheap as hell!
I run one 6" 440cfm can fan and a carbon filter in my room, and it keeps my temps at 76 degrees max, with the 1000W on, and the door on the tent closed. I have one window of the tent opened where the exhaust fan runs out, and the temps are always perfect. That being said, in my previous 5 grows, I used a lower quality bulb, and I ALWAYS had temperature issues. I was running my can fan and a standing fan, with the door and a window completely open, and temps were always at about 77-80 degrees. For some reason, when I switched to the Ushio HiLux bulb for this current grow, my temps dropped, and have been totally stable at 76 max for the last three weeks. They usually hover a little lower than that, at about 74, and I can get the bulb like 12" from the canopy before it gets too hot. With a 1000w, that is AWESOME.
To cool your 3 1000w bulbs, you'll probably need a 6" can fan pushing air, and another one pulling air out of your garden. Depending on your space, you may also need an air conditioner in the summer months. I always recommend running your light cycle at night as well, when it's naturally cooler. I run plants from 6:45 p.m. to 6:45 a.m., for example. I never have to deal with the natural heat of the house at that time. I also flower in my basement, where the concrete walls keep it nice and cool as well!
Happy growing to you!