What type of window? Can we see pics of the interior and the exterior? There is no yes or no answer without context. Help us help you.

Is there a way to attach a pdf file?

Picture would be better than a drawing if at all possible. What about the interior?

Those are the best pics I have right now.

I think you're finie going with (1) 7' and (1) 8' wide unit if you cannot go with 2 the same.

I don't understand the goal. One new 7' unit is installed, and the other 7' new unit is sitting there leaning against the black slider it will replace, so you are going to throw it away and order another 8' long unit to gain about <4" of glass width in each window?

And the windows are (3) units mulled together, so there is a hefty mullion breaking up your view. If you wanted a view, you would design a wall with large picture windows and no mullions.

Also, the windows define, or are defined by, the spaces they serve. So the closeness, or separation, of these two 7' units next to each other should adhere to something.

We would repurpose the 7 ft window to another location. The mullion problem is moot at this point. That is what we ordered and would create a more expensive problem if we changed to window without mullions. The 8ft window panes are significantly better to view out of compared to the 7 ft windows. My primary question is if we did put a 8' next to a 7' of the same style would look ok. I think at the stage we are at it comes down to cost and preference.

I don't think the small glass width increase can be considered "significant." It is strange to have 2 different size windows, yet so close in size but just a little off, in the same plane, so close to each other, with no demarcation of anything to justify that choice. Go with your first instinct and put in the 7' window you already have.