Business expanding to neighboring building in same parking lot - fiber or wireless bridge?

I'm tempted to suggest the business owner run fiber between the buildings. I know it would be a better link than wireless bridging, but I don't have any idea on the cost. The buildings are approximately 100-150 ft. apart, separated by an asphalt parking lot.

Google Map of the 2 buildings

Not crazy far.

I've looked at AirFiber, and Nanostations, and will happily consider those.

My plan with a fiber setup would be to share internet and DHCP from the main building, so there was only one router. The fiber link would go into a switch on the other side, and would simply be an extension of the current network. It would be a full 1Gbps link (possibly XG in the future). With AirFiber/Nanostation, can I still have DHCP come from the main building? Can I have the two buildings be on the same subnet? Or do I need a router to route traffic between two separate networks?

My experience would lead me to want to have one large network rather than 2 smaller networks linked together.

In the main building, they have a Ubiquiti Unifi setup with a USG, 3 AP-AC-Pros, and a 48-port PoE gigabit switch. Comcast business cable internet. In the new building, I'd plan on having a Unifi PoE switch, and at least one more AP-AC-Pro. In the main building, there are probably 20 computers. In the new building, probably 10 more. All-told, there are probably 50-60 total devices (including a couple cameras and guest wifi users).

If we did a wifi bridge, would it need to be roof-mounted?

This is a street-level view of the 2 buildings.

Thanks for your advice, reddit.

EDIT: Wanted to ask what others have spent running fiber in a similar setup. I would expect between $10k-20k to cross a paved parking lot, but that's just my imagination.