depending on if you want to do more running or playboating i think the Juice would be a better runner because of slightly more volume, and i have a friend who has one and he weighs around 200 but he really likes the boat and it floats his weight well, if you are looking for playboating and running, i think you should consider a different boat alltogether because both these have a rather large volume for your weight if intent on playboating, you could look at the jackson fun series, wave sport ez, riot nitro 58, or a pyranha s7 2 are a few suggestions of boats that could play better for your weight but still run rivers.
If it is just between the juice or big ez i would lean towards a Big ez because it would give you a little more play ability for your weight.
But i think your height shouldnt be a problem getting into either of them, although i am 6'1" and 207 pounds and thought the juice was a little too roomy and i didnt have total control on the boat with my legs, i havnt tried the ez but i know the juice is incredably easy to roll because the outfitting sits really low in the boat and the edges slant a lot, i think the edges on the ez also slant a lot so rolling shouldnt be a factor in either boat.
Deffinatly demo if you can get a chance to though and consider more what type of paddling you want to do before purchasing one, but pretty much which ever one you can get a better deal on would be what determines it for me, because it can cost quite a bit to get all the proper gear if you want to buy quailty equiptment.