im about 360 myself (really need to lose some but thats another discussion) and i hunt out of an API grand slam MAGNUM rated for 350lbs. its quite comfy, and i get in it, move all around, jump up and down and its not going anywhere.

stand manufacturers rate the stands at 350lbs but in order to rate them at that weigh they must repeatedly test and prove the stand can hold more than double the weight. meaning the stand is tested to 700+lbs and can not fail. they just dont tell ya that kinda stuff.