Followings are wireless routers that are officially supported by OpenWRT, you can simply buy any of these and flash it with OpenWRT by following the instructions of that model on the OpenWRT website.
1. TP-Link TGR1900
2. ASUS SRT-AC1900
3. NetGear R7800
4. Redmi AX6000
5. Redmi AX6S
6. Redmi AC2100
7. Xiaomi CR6606
Followings are Single Board Computers that can run Debian or Ubuntu, you can buy one of them and install Debian or Ubuntu on it to set it up as a router or a 24*7 running server.
1. Wyse 3040
2. R2S
3. CWWK x86-P2
4. HP t640
5. Wyse 5070
6. HP t430
7. HP t240
