For the Ultimate I would highly recommend a HiMax 2812/0850 with an 11x4.7 APC SF prop and a 1320 mah li-po. That will hover it at 1/2 throttle and give you nearly 20 minutes flight time doing mostly 3D flying. I have the Eflite Ultimate with the HiMax 2812/0650 with APC 11x4.7 APC SF prop and a 1320 mah li-po and hover at about 5/8 throttle with 20+ minute flight times. I personally would get the 0850 if I had to do it again though. The HiMax motors are direct drive so they are quieter and have fewer parts to break due to no gears. My Ultimate is currently 14.4 oz AUW weight. The HiMax motors come with 3 mounts including a stick mount, for about $65, so you can easily put it on a different plane later on. These motors will bolt right onto the Eflite Ultimate without a single mod required.

Get a 20-25 amp ESC for the 0850 and a 10 amp for the 0650.