storing cc details in mysql

Hi, I know this is an old chestnut and i am going thru archives and googling as well. anyhoo, my small company recently decided that live cc processing was too expensive for our needs (this has to do with us being based in ireland where there is a problem with the banks -they only deal with one irish company to process and its too expensive for us - don't really know the details but thats what i was told). so we're going to store the cc numbers and process manually(we're a small company at present so we're not talking 1000's of numbers just yet). i'd appreciate anyones experience or advice regarding storing in a mysql db - articles etc.. i also have the option of using postgres (haven't used it before) if anyone thinks i should. as a side note - i notice that phpshop stores cc numbers in mysql.any thoughs on that - i.e. is it a good example of how it should be done. many thanx, adrian murphy