Hey guys, thought I'd post up a couple links for future reference
First one, Goodprint UK, is where I got my business cards. They're pricier than Vistaprint, but often have good sales. There is one going on at the moment, plus this 50% off promo code that is valid until June 18th "MAH238"
Goodprint has a variety of options like the shiny gold cardstock mine are on, and in general their paper and print quality is very good. They also offer rounded corners (and you can pick which corners to round if you want round and square) for only 2 quid extra per 100 cards.
The other link is for crafty things - Craft Superstore. They have nice and cheap cellophane sleeves and envelopes or blank cards with envelopes, and even with the cheapest delivery option my orders have come two days after I placed them.