Well, I love barn lights. I think you should go fr it, but agree that one centered over the garage doors would feel better. I also like the sconces linked below. I wanted them for my screen porch, but they were too pricey. Thanks to Trailrunner, we know they are on sale at F+F! I'd use three of these....one on either side of the garage doors and one at the entry door. And YES to window boxes. I don't see why funky barn lights preclude window boxes. Look for the self-watering ones to make the job easier. Here is a link that might be useful: Barnlight sconces

"We have a brand new build with a HERS rating of 53................ The issue is the master is subjected to the added temp stress of both the hot summer and cold winters in Ohio." How new? I take you've had at least 1 winter and 1 summer there already? If the garage ceiling is insulated to its full depth then you'd have to add a false ceiling to increase it. Alternatively, you could remove the fiberglass insulation (I'm assuming its fiberglass) and use spray foam for added R value. Both of these involve a lot of construction, though, and would cost quite a bit more than your initial $300 budget. If the house is new and HERS 53, isn't your builder responsible for this issue? (A HERS 53 score is significant because it's a Presidential Award threshhold that builders tout when trying to earn your business!)

i'd prob do a warmer tone, charcoal. (nothing too silver to too blue gray) and think about adding some type of iron hardware to the door Chelsea, Amherst or Kendall are warm charcoal tones Storm is a lighter, neutral gray, Whale is blue gray, Galveston is too taupe, and the others would be too light, or too dark.

In the long run, I would change up the siding above the garage doors, as Tozmo suggested (I would probably wait until I was painting the exterior to tackle it, though). Add some horizontal trim to divide the two siding zone. Change the direction of the siding, or switch to a wide board-and-batten siding, or do wall shingles. Googling "mixed siding homes" turns up lots of examples. If you are into holiday decorating, you could reserve the space for a giant spider at Halloween, a huge wreath (or pair of wreaths) at Christmastime, and a flag for the 4th of July.