I sympathize with your enthusiasm to get your landscape done but please be aware that plants are the last thing to buy in installing a landscape design, not the first. It is impossible to create a successful landscape with an assortment of plants one bought in advance.

I deal with this all the time--and made the same mistake myself many moons ago. Figure out your design, with or without professional help, depending on the budget. Then install the hardscape and then the plantings. Good luck.

Just an aside....loropetalum IS an evergreen shrub, although depending on your zone, it may be of marginal hardiness for you. In colder areas, it is often semi-evergreen, meaning it will drop foliage in colder weather but not all of it :-). I understand your intent with it, but you should realize that plants with red (or burgundy) foliage that hold that foliage all year are part of a very short list. An alternate possibility is one of the nandinas or heavenly bamboos that colors well, like 'Sienna Sunrise'. Nandina is considered invasive in some areas of the country, so check for specifics where you are first.

If you do not plan to reconfigure the planting areas or modify the current hardscaping, then plant selection IS your primary design consideration. I'm not sure you are putting the cart before the horse if this is the case.

Did you take your house photos with you when you visited the nursery? Most garden centers, especially at this time of year, will have staff that can work with you and your photos to develop a simple yet effective planting plan. For more extensive design input, you may be better off hiring a professional for at least a consultation, if not a full plan.

You mention in your other post that you think the gold may be lost against your brick color. If you plant a dark green evergreen, and the gold in front in a second layer, it will show up nicely, if the gold is what you want.

If you want a red for winter, you could possibly plan on using a second plant, instead of relying on one to carry you through the year. One of the red twig dogwoods, planted in a large clump at one end, might give you the punch you want in winter when your other reds have lost their foliage. Or maybe a Winterberry Holly, a deciduous holly with bright red berries. Both lovely against snow.

When you say symmetrical plantings, do you mean literally a mirror image, the same on both sides? I wouldn't with your house, which is informal in style. If you mean a fairly ordered planting with a lot of repetition of the same plant, that's something different.

You do seem to be rushing into it a bit, and I can understand your impatience to get it done, we've all been there. The suggestion to ask at nurseries for design help is a good one. You may also know by now that with the cost of plants being what they are, an investment in a professional design can save you not only the angst of worrying over every decision, but time and effort wasted, as well as money wasted on mistakes.

I've said it many times, and I speak from experience. Going to the nursery with a professionally done planting plan in your hand and a plant list is SO much more fun than doing it the way you are doing it. Even if you do the installation over a period of a few years, you are always moving toward a known goal, with no false starts, no guessing, and no gnashing of teeth. But if you're determined to do it yourself, go ahead and try. At least you are putting some thought into it, and you may make some mistakes, but you can always move plants that don't work to another area and try again.