How heavy are you？
How heavy do you weigh？
都可以
二者都有寻找的意思，hunt for常指猎取，或者找工作,search for强调搜寻，search some place for sth.较常用。
hunt v.打猎, 猎取, 搜索, 搜寻, 猎获
n.打猎, 猎取, 搜索, 搜寻, 狩猎
做及物动词时：
hunt the county在这郡中打猎
hunt the hounds用猎犬打猎
hunt the cat out of the kitchen把猫赶出厨房
They hunted him down and strung him up.他们把他捉住然后将他捆起来。
做不及物动词时：
vi.打猎，寻[探]求, (仔细)搜索[寻](after, for)
(兽类等)猎食
hunt for a lost book寻找遗失的书
Wolves hunt in packs,狼成群猎食。
search
搜寻; 检查，细看; 察看; 调查; 探求; 查寻，(寒冷, 风, 火等)侵入, 进入...每个部分; 穿过
search a person搜身
search one's memory寻思; 追忆
search one's heart扪心自问
search a house for a hidden weapon在住宅内搜查武器
search a wound(用探针)探伤
search sb.'s face察看某人的脸色
The cold wind searched every part of the city.冷风吹遍全城。
参考资料：金山词霸