You can certainly get the look that you want and depending on the window and performance that you pay for, the performance offset will not be that bad.

Most 2x4 framed walls perform at and average R-Value of about R-7 to R-9.

There are window systems that are R-6+ without particularly exotic materials.

In conjunction with a high performance window, you would be well advised to consider some additional thermal shades or curtains to slow additional heat loss from the space.

That does sound like alot of glass. Not sure what kind of heat the home has but radiant would be a good option. Would be more efficient and "feel" warmer too. The most efficient windows are of course a good idea :)

Thanks. Any particular window manufacturer that you recommend? Who should we not use? Are triple pane worth the cost?

What do you want the windows to look like? i.e wood, fiberglass, vinyl, etc?