The Wyeast and White Lab blends are designed to be pitched without using additional ale yeast, but you'd probably be fine either way.
One possible concern is that you are using a small oak barrel, which has very large oak to liquid surface ratio, so a year might make it over-the-top oak-y. If the barrel has been used a bunch that would help, but if it's only been used a few times you might want to consider leaving it in the barrel for a shorter period of time.
Also, when you transfer to the barrel make sure you also transfer a good amount of the trub too. The brett strains will feed on it and produce esters which will help with complexity.
According to Wild Brews, raw wheat works the best but lots of people on here use malted and/or torrified.