Windshields/lip selections are hard to make because not everybody is the same size and, even if they are, their perception of what is "clear air" may not be the same as yours. Of course, the worst part is, you'll never truly know until you buy and try.
That being said, the KLR is the first DS I've owned that had a "windshield" and I hated it on the first ride. I'm 6'4. I looked around and chose the Madstad Adventure shield. I had it on the KLR for a couple of years and was relatively happy with it.
Then, one hot day, I took it off for a ride to try to stay cooler. I couldn't believe it. The ride was vastly superior without the windshield as opposed to it being there. No more wind buffeting coming around the edges of it; nothing but a smooth flow of air passing my chest and helmet.
It's been off ever since and I doubt I'll ever put it back on. I think the key is that I retained the Madstad metal mounting plate that slid in where the stock windshield was. It's shorter than the stock windshield and just a flat, curved, piece of metal. No turbulence or "blast" comes off it at all.
I'm so pleased with the "short windshield" that I encourage all looking for smooth air to try it. Take the stock windshield all the way off and go for a ride without it and see what you think.