I have 案底 too, but I apply tavel visa is no problem , I got 10 year travel visa.
But if you go to work long time, must have company hiring you and apply the working visa for you. And if you just go short term, if you are work for your hk company,the your company also will give you a company letter go to apply, it be must easy. it depends on your company is what kinds of business.
http://www.unitedstatesvisas.gov/