I too had considered that Ultimate, and ended up going with a magic 3d instead (had all the small stuff required for that, so it was the cheaper route for me)
Here is a great review on the ultimate, along with the mods the writer made, and some assembly shortcuts, hints, etc
http://www.hobbypeople.net/review/123820man.htm
He had no problem balancing with a 91 magnum 4 stroke.
Good luck, and post pics
Steve