Everything you want to know about loops.
The rectangle will be directional. Try to make it some multiple of a quarter wave (3/4 wave minimum) for the lowest band of interest and as close to a sqaure or circle as you can. The takeoff angle for a loop becomes useable for long distance communication at 1.5 to 2 wavelengths of the lowest band you want to use. At 1 wavelength the thing is basically shooting straight up and straight down. Think about a quad beam that uses a 1 wavelength elements. It shoots out of the hole in the square. As the frequency increases to 1.5 to ideally 2 wavelengths it starts to radiate off the sides. You mentioned 200 ft. If you can find some way to add 80 feet you'd have 1 wavelength at 80 meters and although it would be an NVIS antenna for that band suitable for local communications (and really, on 80 thats all I hear) at 40 meters you now have a 2 wavelength loop that will have a useable takeoff angle and on 20 it gets even better.
Thats all I know for now. I am installing my 440ft (close to 3/4 wave on 160 1.5 on 80) tomorrow but I am feeding mine directly with an autotuner from under my second story eave. If thats not an option, then open wire line and a tuner will be your best bet.