B-1 is quite straight forward, no real formal sponsorship needed from a company or anyone. Having an admit to Alchemist should suffice. H-1B is a very different process where in visas can only be applied in the first week of april and if you win them in the lottery (lesser than 50% likelihood) then you can come in October.
It may also depend on what country the applicant is coming from.
There are limitations with B1 in that you cannot work formally. Also you cannot be in US for more than 6 months at a time or for more than 6 months in 1 year. And if you stay say a cumulative of 1 year over 2 years, then you get a warning as in when you are entering US an immigration office might warn you that you are pushing it. With H1, it is much clearer and you can come and go as you please.