They bloom in fall and winter -- that is the great thing about them! And you have picked two nice varieties. Here is a link to some planting tips. (See below.) The main thing I have found is to plant them high in a wide but shallow hole, so they will not later sink below grade. And use plenty of good planting mix (it is worth it). Give them plenty of water during dry spells for the first couple of years until they get established. Here is a link that might be useful: Camellia Planting Tips

There is not anything particularly disturbing or "wrong" about its location. It's far enough from the house that it's not going to be harmful to it. If you like a shady yard, you'll have it. Even though in the future it will rob your perennials of the light they need, that is the nature of gardening and the constantly changing, albeit slowly and thank goodness, conditions. You give something up but you get something in exchange. Shade necessitates groundcover instead of lawn when it becomes pronounced. No big deal. Slope necessitates groundcover, too, so you might end up killing two birds with one stone. If you decide you don't want that kind of a yard in the future, you could move the tree as it is not that big. But moving it requires some skill. You still want to keep a solid root ball. (It would be hard to explain in words, without using an awful lot of them, how to do it.) Best if it is done when the tree is completely dormant as it gives you a better chance. You also might want to trim back all the branches to half their size in order to increase your chances of success. Everything will regrow after it is situated.

Do you have any things you'd love to see every day? Do you like surfaces to stay pretty clean or do you like a lot of things on there? What are the colors you like? What kind of decor or other things do you find yourself drawn toward?

Talk to your excavator, they should be the only trailer besides backfill, and they can unload at the street or if you already have the drive installed, they can back in. Only thing helpful at the pad location would be a turnaround, that just depends on your soil type if you're not dumping gravel for that. If you have a basement or sloping site needing graded, the bucket or blade will be tracks so the pad condition isn't important. If just a slab on grade it'll probably be a backhoe so soft spots filled and stumps ground around the pad perimeter. Concrete and delivery trucks after that are probably all tandem axles so they're used to 3-point turns. For a well rig can't run a construction entrance to where that will probably be.