I'll give you the part number at Autozone for one that is a direct replacement.
Here we go:
Part number #156860 98090......they are $0.89 each
I think all you need is the 98090 number.
Compliments of '05GreenMachine' - Front wheel studs can be replaced by using the front wheel studs from an '03 Banshee. The only difference is the Banshee studs are black.
Also, for those of you who want replacement lug nuts for aftermarket style wheels (i.e. Douglas wheels) you can pick up the following part number at AutoZone.
Part Number #494879 983-110......they are $1.79 for a pack of 4.
Those nuts and studs are M10-1.25 and the nuts use a 14mm wrench/socket.
This is from an old post that Crazie made on Z400central so the part numbers may have changed so if they have just ask for the correct size and you will be fine.