I'm wondering where you got that 8 week figure. Because if your company has told you that they will give you this time off and your job will not be at risk, you need to get that in writing because they are not legally required to do that and without something in writing, they'd be (shittily) within their rights to up and change their minds.
If the 8 weeks is something you believe you qualify for via short term disability, please know that even if you qualify for disability, if you don't ALSO qualify for the job protection of FMLA, your company doesn't have to let you take the time, which is why I asked if they've actually stated your job is secure.
As for paternity leave, that just varies company to company so your husband would have to ask. But he would likely qualify for FMLA (assuming he and his company meet the guidelines) which means he could take 12 weeks by maxing out his sick/vacation time and taking the rest unpaid.