Setting up fiber bridge between Netgear routers

This is another one of those “setting up a network, need some help, and I’m a bit ignorant” posts. I was referred to the Netgear community from a reddit post. I know this isn't quite the right forum topic, but it was the closest I saw. This is a fairly general question for now. Anyway, here’s the gist…
A. We have two buildings: (1) main house & (2) second house, which is a double-wide approximately 30 m (~ 100 ft) away. Need WiFi in both. Plan to hardwire between the two buildings.
B. We currently have an old Nighthawk AC1900 (R7000) router/access point (AP), which we plan to move to the second house. We will be buying a new router for the main house.
C. My current plan is to bury a fiber line from the main house to the second house. I was told by the ISP that I should run the incoming internet to a router instead of directly to a switch to split before fiber. So, my planned setup will look like this: internet > router 1 > media converter 1 > fiber > media converter 2 > router 2 (AC1900).

The questions…
1. I like Netgear so far, and figure I might as well stick with it. Any recommendations for which router to purchase as router 1 for the main house that can take incoming internet and send to router 2?
2. Do I need to use a POE device to run to media converter 1 > fiber or can I go straight from router 1 to media converter 1?
3. Which type of fiber line should I bury? I’ve seen conflicting recommendations and I’m a little confused.
4. Do I need to be careful with selection of media converters or should anything work?
5. Is there a foreseeable compatibility problem using the AC1900 in the second house with this setup?
6. Anything I’m overlooking or being stupid about with this plan?
Many thanks in advance!