ESA as disabled student - CB or IB?

I've been told by my university which Im due to start in September that I can claim ESA as a student, as I'm in receipt of DLA.

I've been advised that I'd still need to go through WCA, but it's guaranteed that I would get ESA, it's just to look at if I go in SG or WRAG, is this right?

Also would it be CB or IB?

I've got a partner, can I add him onto my ESA claim? He is taking a career break to look after our child for the first year and therefore cannot claim benefits (apart from housing benefit and carers allowance)

Thanks!