Networking issue hardware recommendations

[ToxicFire]

I need to figure out the best approach to solve this issue, I have access to the internet through a remote open wifi hotspot (far enough away that it requires an external antenna) I want to create a secondary wifi network thats separate from the hotspot with a diffrent SSID in addition to having secure access that routes all internet bound traffic out to the wifi hotspot. Now my instinct is to look at wireless bridging but most range extenders and wireless routers i look at that have capability to support external antenna's seem to only have WDS bridging which creates a transparent bridge using the same SSID and same security and access controls. I could probably do it with a linux box but i'd prefer a more dedicated piece of hardware for the task. (I wonder if buying a device that has WDS and simply flashing custom firmwire like Tomato or Open-WRT would allow me to do what I want)

 

So any advice or recommendations on hardware or other suggestions much appreciated.