IMo you will never match the stone and why just do a nice glass and metal railing to match the windows a renew the decking or strip it and stain to match the interior floors . As for the open area a simple marine plywood painted green with plants in front would work or build a planter there

Thank you, I like the planter idea

Something open like this would offer a lighter feeling:

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Down the road, you could do a lot more with your landscaping :

--Plan taller shrubs or interesting grasses up against new railings. Choose plantings that work with your light conditions.

--Edge your lawn near the garage area.

--Either top coat your cracked driveway or replace it with paving stones coordinated with your stone work for a patio effect. We can't really see enough of your yard to make good recommendations. Add some photos from farther back.

Would advise against the concrete and stone deck. If you were to install concrete foundation walls for your new deck they would be right up against your wood framed walls with siding. This will cause problems as water will seep into and sit in the space between the concrete foundation wall and the wood framed wall which will eventually cause a rot problem. Would suggest you stick with wood structure for the deck.