I have a set of McGard lug nuts I have used on two different rigs and they are holding up great.
If you do search for McGard Lug Nuts #64805 1/2 x 20 RH you will find them. I bought mine from Summit Racing at the time because they had the best price. I would bet that Amazon would have them now for a good price.
Where ever you find them they will not be cheap. Mine are about 5 to 6 years old.
Joe
Here is the Amazon Link:
McGard