SigMan

The Himax set up with the CC Phoenix 25 would be a good match for the Ultimate. Here's a link for a combo deal that is $99 (+ about $8 for shipping) for both......very sweet deal!
http://nesail.com/detail.php?productID=3222

You can check out the ratings on the page for various props. If you go with the 12" prop just keep an eye on the motor and batt temperature when flying. A 10x3.98 prop will give the longest flight time but with less thrust than some of the other prop combinations. The 11x4.7 prop is probably the better combination when considering flight time vs. motor and batt temps. There are some other great combo deals on the same site so browse around and find one that works for you.