I have placed many orders at thewhiskyexchange (from Denmark) without any problems at all, fast delivery, good wrapping, good service and not to forget good prizes
... I'm very satisfied
As for encrypting the transaction, there is alot much much easier ways to get them than to trying to rip them on the fly, what is more important, do they have a secure database ?
Or you could just go around the local shopping center finding some reciepts with all the info on you need.
SSL or other encryptions are good for transfering confidential data, but your creditcard number is not confidential....