Heather,
As both a fellow CD'er and an avid golfer, I'm not sure that I'd go far beyond a sports bra and panties. There's a reason why women wear sports bras.
Imagine standing on the tee and taking your stance. Most golfers have a tendency to drop their shoulders somewhat just before their swing (if you don't, you're robbing yourself of significant distance). That's when your bra strap will likely slide down your lead shoulder and your swing will go to hell. You can either adjust your bra strap in front of your foursome or while you're looking for your drive in the cabbage. Not great...
A garter belt would rightly be out of the question and I don't think suspender stockings would be a significant improvement. I can't imagine that crouching to read a putt would be good mix with any kind of stockings. Again, you could continually adjust your stockings in front of your foursome (which kind of defeats the whole purpose of underdressing in the first place) or play most of your round with your stockings around your ankles. You may be able to get away with panty hose I would imagine.
Anyway, I've never done it so you can take my opinion with a large grain of salt...
