You have two good options, and several adequate options.
I like the AeroFlow
stuff. Their screens are designed to produce smooth laminar flow, and they just flat work. Adding the AeroGards puts you in a smooth, quiet bubble that's all-day comfortable. They are a bit large, and a bit pricey when you add the side guards, but they do work very well, solo or two-up.
Another good option is the Cal-Sci
screen. It's closer to the stock screen size and shape, but optimized for smooth airflow, so it works much better. It makes a great solo screen for those who want to stay a bit smaller and sportier.
There are a few other screens available for the GT, but in my experience (and yes, I've tried them all), the other options are better than stock, but not as good as Cal-Sci or AeroFlow.
From your description, I'd say the Cal-Sci is probably what you want. Contact them with your measurements and preferences, and they'll help you pick out the right size screen for your needs.
Just don't be surprised when it works so well that you don't feel like switching back to your old screen during the summer . . .
'13 Dark Graphite Metallic K16GTLD, 24K miles and counting...
'09 Magnesium Beige Metallic K13GT, 60K miles miles and counting...
'02 Mauve Metallic K12LTC, 106K miles and sold
BMWLT#145, IBA# 366, MOA# 111996, SCMA# 24032
All lower 48 states plus Alaska on the K13GT in two weeks . . .
Some people see the gas tank as half empty. Some see it as half full. All I care is that I know where the next tankful is coming from...