MTB front hydraulic disc break caliper (and rotor and lever) wanted

Hi there, I've recently got back into cycling, mostly road, but I also own a cheap, old, GT Aggressor.

I ride this bike at most about twice a year, but the front caliper has totally broken (I don't think it was a standard one anyway) - this has gone in the bin and i'm looking for a replacement hydraulic system but given the lack of use I don't want to buy new - does anyone have any suitable old bits lying around they don't want that would work? I'll need caliper, pads, brake lever and if my standard rotor isn't compatible a rotor as well.

Thanks in advance.