Recommendations to upgrade equipment

[nitro001]

Hello,
I am doing some IT work for a church and noticed they have a very weird network setup.
They have a Buffalo wzr-hp-g300nh (330N) supposedly High-powered router as its primary router (Providing a private WEP access point (Faith).

They also have an Amped Wireless High power Wifi-range extender only about 30 feet away from it, only it doesn't repeat the SSID, it generated its own Faith_RE. Not sure the model as it is secured to the wall.

Finally they have another router, forget the brand, which is on the other side of the building providing a public access point (Faith_Public), but also relays their security system, which was a bit scary when I found this out.

I used a Wifi Analyzer on my Pixel XL to see performance and near the back router the main access point is visible barely (-82db), the repeater is available (~50db), similar results in the front the public access point is almost non-existent.

I would like to eliminate the extender as it is causing issues and needs to be rebooted once or twice a day, but in order to do this, I need a more powerful initial router. There is no cable outlet where the extender is or I could put the primary router around there and make it more central.

I run an ASUS RT-AC66R at home with Merlin's enhanced firmware and I understand the RT-AC88R has a fairly powerful antenna as well and these support a secondary guest network segregated from the primary, so I could also eliminate the security issue of hosting the public network on the security camera router. Just not sure how these compare to what is available out there.

The building itself was built in 2008 so it is all sheet rock, no plaster, but it is not a direct line of site between the furthest points, and a set of bathrooms in-between.

Thanks in advance for any suggestions.

Nathan

 

[nitro001]

I wanted to clarify some additional points.
the third router that I forgot the brand is an Edimax BR-6478AC V2 Router.

Also i did some measurements over the weekend using Wifi Analyzer for Android. from the main office, The main router comes in at -38db (channel 6) and -56db (channel 11 ad-hoc) which it should be better considering I was standing right next to it. The Repeater came in at -58db and it is about 30 feet away. the Public one hosted on the Edimax router came in at -76db for 2.4GHz and -90db at 5GHz.

From a second office, near the repeater, the main router comes in at -53db on Channel 6 and -63db on channel 11 (Adhoc). The Repeater is measuring -58db but I was standing around the corner from it. The Public 2.4GHz was -76gb and Public 5Ghz was -90db.

From the conference room, near the Public point (Edimax), the main router is still visible (barely) on channel 6 @ -82db. the Repeater is measuring -64db and the public access points are -34db for 2.4GHz and -47db for 5GHz, which is better but still low considering I was a couple feet from it in direct line of sight.

I have a couple more measurements as well from different points in the building, but it is similar. all thee are visible in some capacity, although could be very low.

Again, any suggestion would be helpful. Even if it means going to a mesh style network.