DD - I would recommend my vet, Peter Mason at Stowe Vets, he is fantastic. Ask for Peter Mason though, as some of the vets there aren't specialist horse vets. 01449 776201
Out of interest, are you buying a horse from Bardwell - would be interested to know where/who from as I know a lot of people in that area...
Also, Swaynes haven't got a specialist horse vet anymore (I have never used them, but our friend that used to have the chap from Swaynes has changed vets since his retirement).
I think you will be pushing it to find a vet that can do a vetting tomorrow. You could try Rossdales in Newmarket, but they charge an awful lot.