Thread Size is M14 x 1.5, and OEM Hex Size is 21mm
I just put new lugs on my '07 SE, choosing the McGard Installation Kit (part# 84524 - includes four chrome locks, 16 chrome lugs and 4 chrome valve stems). They fit perfectly and look fantastic! Bought 'em from JEGS (you'll have to call, they're not online) for around $75 including shipping. If you're going, I'll gladly show them to you in a few weeks during the VT Cruise In.