Getting USA PSN CARDS For UK

I live in the UK and im trying to find a website in which i can can purchase a USA PSN Card as theres loads of PSOne Classics i want to download. i would perfer to have it so they E-mail me the code (so i dont have to buy the card then pay for the shipping and have all of the wait for it to get here) i know theres sites that do it and i have heard stories of people using it enough to know somewhere you must be able to get it.

Im also aware theres going to be a fair amount of sites which which offer this service are abit dodgy so if anyone knows a good site which they personally have got Codes from in my same situration or know people who have then please share this information with me please...

Also who thinks the Playstation Store would be so much easier no matter what country your in if they give you the option to be able to use PayPal.

I don't think you will be able to use a US one on the UK store, I am in Australia and bought one in the store and it had an Australian flag on the front so you might want to be careful with that. Unless you have done reaserch in which it says they are compatible.