You may want to take a look at Sunrise Windows. They have a narrowline sash and sill like you are looking for.
It's another brand I'm a dealer of besides Schuco. They don't have locking screens, TPS seals, shadow grooved welds, etc. like Schuco, but they do have their own list of exclusive options and features that make them very attractive and worth looking at.
They are available in triple which puts them in the same general U-factor range as Schuco and other super efficient windows. U values with triple glazing range from .16 to .22 depending on the window type.
They also have some color combinations that most windows don't have. Besides the normal white in/out, you can get tan, sandstone, and earthtone on the outside, with the inside being a different color such as white or one of a selection of woodgrains. The windows are co-extruded, not painted, so you don't have to worry about paint coming off over time.
Sunrise also has blinds and sunshades available between the glass which is really nice. They have recently added doublehung windows to the list of windows and patio doors that are available with this option. The blinds come in 7 colors and the shades come in 5.
They have also recently come out with one of the nicest folding handles I have seen for casement and awning windows. Very clean.