Just remember to loctite those studs in using the recommended product or they may walk themselves loose. Also, with wheel nuts get one piece solids not those el cheapo chrome capped ones as the caps WILL loosen and just spin when you try to remove them. The quality of the nuts are as important as the studs themselves. Good luck, I think you'll like them and of course pics when installed please. JIMLooking around and found Grayston engineering (who are manufacturers I believe but don't sell on their site http://www.grayston.biz/wheelnutmenu.htm ).
Demon Tweeks sell them http://www.demon-tweeks.co.uk/performance/wheel-nuts-bolts/grayston-open-wheel-nut?iurl=http://www.demon-tweeks.co.uk&iid=1838983&sid=4&numAttrib=2&attribs=Head+Size~19mm@&brand=&code=&attrib0=select&attrib1=Head+Size~19mm&quantity=20
Depending on size around £1 each! So £20 and you have your studs done then just need nuts which they do for £1.15 each so full stud conversion for £46...!