Co-sponsorship/Temporary UK Accomodation/The quickest post??

So, having just realized (DOH!) that we need notarized copies or originals (not regular copies) of our co-sponsor's financial info and our temporary living accomodations till we find a flat........

Should we just scrap the idea of using my husband's mum (in the UK) for financial support and temporary residence, and instead use my mom (in the US) for financial support (she's already been thru the co-sponsor process from when we got my husband a US visa) and just book a hotel to show temporary residence?

Or, does anyone know a very fast and reliable way of getting documents from the UK to the US?