My understanding is that H1B1 is not considered a dual intent visa, and so adjustment of status to lawful permanent resident isn't possible. Its history lies in a free trade agreement.

There are also annual limits for H1B1 but they are less likely to be reached. https://www.dol.gov/agencies/eta/foreign-labor/programs/h-1b

Whomever you hire on H1B1 just note you will almost certainly lose them after their visa extension completes.