Lugs/nuts, need input on right one's....

I'm having continuous problems with the front lugs/nuts, never the back, just the front. I'd like to know if anyone can tell me where I can get replacements for one that broke off, and for future. I'd prefer somewhere around town - really don't like to order over the net.

Also, can I get the exact measurements of what I'm looking for? For the front, on a '97 stock steel wheels, 16x6".

Thank a much!