Too Tall to Stand??

[Texas Gasser]

I'm roughly 6'4" and do most of my riding on flat to fairly hilly open and wooded trails... I haven't been riding long (maybe 2 yrs.)... I would consider myself a mostly sit-down rider but I am trying to learn the stand-up technique... My biggest obstacle seems to be my height... Because I am so tall, I find myself having to bend way over at the waist placing me too far over the handlbars without enough weight on the pegs...

Do any of you have experience with "handlebar risers?"... I know they are available but am wondering if they really work well... Are they strong enough to withstand the pressures of enduro/trail riding?... Do they create any problems with bike handling or steering?

Thanks!!