Newage WRX rear brake options

I have a Newage 53 plate WRX with Brembos fitted on the front combined with Performance Friction discs/pads.

My problem is that my rear (standard, non Brembo) pads and discs will need replacing soon. I also have a major binding problem (on rear), so I'm thinking my calipers will also need an overhall, which if I am correct in thinking will involve at minimum new seals and possibly one or more pistons.

I see my options as being:

1. Fit second hand Brembos, skimed discs and new pads.
2. Overhall calipers, and fit new aftermarket dics and pads.
3. New or second-hand aftermarket set up such as stop tech etc.

Any thought would be greatly appreciated. Budget is tight so new AP's are NOT an option!!!!