I have really bad DSL where I moved so I recently got a cheat USB hotspot. I want to bridge the hotspot to my current router because it’s a great router and everything is already connected to it.
Assume my max DSL speed is 3/1 Mbps 
and Max hotspot speed is 16/4 Mbps what would be my best choice for price and performance? All 3 Routers support OpenWrt, AR150 is the cheapest @$20, 150 and 300 are very pocketable too.
Other things I’d like to do is:
Subscribe to a VPN and set it up on the GL router
Dual WAN. Have the USB hotspot and DSL plugged into the GL router
Dual WAN failover, cell to DSL, and probably link aggregation if it’s possible with OpenWrt
I can get higher speeds with the USB hotspot, over 60 Mbps, just not at home but it will mostly be used in the house.
Any advice would help.