Once again, an MR-16 IS a normal halogen.
Halogen lamps are about 3000-3200K color temperature.
MR-16: A miniature reflector lamp that is 16 eighths of an inch wide.
The number in the name of a lamp (light bulb) is the physical diameter in eighths of an inch.
As for the power consumption a watt is a watt. If a lamp is 50 watts it draws 50 watts regardless of low voltage or line voltage. You DO NOT save much energy with halogens (or other "low voltage" fixtures). They simply give a crisper, slightly brighter light.
They are not the same as HID or fluorescent lights.
Please post back and let us know how it turns out....