I purchased the studs off ebay, where you can find an amazing selection for really really cheap!
A lot of the studs have the glue implanted in them on the back, meaning they are iron on, however this isn't safe for faux leather items and such. I used a strong 2 part glue (a spray and a glue) to fix my studs in place!
Have a practice on something scrap first.
Good luck! Be adventurous! X