Bob Lee is a "can't-go-wrong" bow, and a good choice.
Widows seem to have a love/hate relationship...I personally am growing into liking mine--but I've barely had it a week.
I know nothing of the Kohannah.
I would most definitely go to the BW place and check them out--I have heard nothing but rave reviews of them letting people shoot anything they want on hand, even if they don't buy one.
But the more you can try, the better you will be.
And oh yeah--I draw 30", and I would tell you to get a 64" Widow or Lee just for comfort's sake.
Even with the rear mounted limbs on the widow, and having it tillered to 29.5", I'm still glad it's not a 62" bow.
Take Care,
Marc