Halogen Pars are a good idea so long as you have the power for them. I generally use around 8-12 500W PAR 64s and 16-36 250W PAR 38s at the majority of my live shows, plus movers and effects as the event requires. While the 1000W Pars are very nice, you might want to look at the 500W versions instead, the reason being you'll have an easier time finding budget dimmers that can handle a 500W load on each channel versus those that can handle 1K. There are also some 575W Pars on the market that are in a league of their own, but they also cost about 4 times that of a 500W model...
The obvious drawback with the halogens besides heat and power is that you'll have to gel the lights in appropriate colors, and short of using a scroller you can only pick one color per can. I'd suggest using 2x 500W Par 64s plus 4x 250W Par 38s per 'group'. That can live happily on one 20A circuit so long as nothing else is on it and you're using a dimmer rated to 20A total load. Gel your 64s light colors and put your bolder colors in the 38s. If it were me, I'd do a group on all 6 sides for symmetry, but if you don't have the budget and/or power you can get away with 3 if need be.
I'll trust that your rigging system is up to the task for this. How high above the stage you need to go depends on how far away from the stage your rigging points are. If they're 25ft back, put your truss about 25ft up. If you can't be as flexible, just do what most do and point the lights at the talent
You can do this for 3k, though it'll be a little tight. What do you plan to use for a controller? Do you have any existing equipment or will you need to buy everything (lights, dimmers, controller, cable, clamps, gels, etc.)? Power and rigging add up fast, and gels aren't cheap either. Luckily, there are some good package deals on the market which can really help you out.