Baking chicken in oven, but keeping it moist
The technique you describe is pretty much just the standard way of roasting a chicken.  A V-shaped roasting rack is excellent for this purpose.  As for keeping it moist, the standard technique is to brine the chicken first.  Done properly, brining a chicken results in a moist, tender bird with crisp skin, and doesn't involve adding any additional fat.  I normally brine by putting the chicken in a stew pot, covering it with cold water, adding about a cup of kosher salt, and letting it sit for 90 minutes.