Can you add the fireplace to the existing chimney ?! Beautiful looking home !!

Hi! I would echo the roof with Pennsylvania Bluestone. Running a seemingly random pattern, like Ashlar, will keep it from fighting with the brick. What type of fireplace did you have in mind? Freestanding? Attached to the house? Part of a larger outdoor room? Matching the brick perfectly will be tough, so once again need to look at other areas/colors to make it work. Where the fireplace is situated will help with that recommendation.

Don't know what material the current patio is made of but you could probably have it stained or do it yourself. You might consider paying a couple of landscape architects a consultation fee to come out to give you ideas or better inspiration, or check with local universities if they have programs where students come out for a chance for "field work" or recommendations. You have a beautiful home, best of luck with your new outdoor space, very exciting.

Because the rock will have the "face" on top, avoid softer stones like limestone. Patio stone needs to be harder than if it were laid vertical on a house. The softer rocks begin flaking and crumbling with exposed weather. Especially if you ever plan on having a pool. Your rock supplier will lead you in the right direction of a rock that is hard enough to take the wear and tear of traffic. Then it's just a matter of picking the right color to compliment the brick. Of course, you could always go with stamped "stone" concrete on top of the existing. It has come a long way in looking like the real deal and the colors are endless.

Looks great! The results are right in line with my original comments and the results are perfect!