In that space I would go with a 250W HID MH/HPS. Over 300W it is highly recommended the grower use Co2 in their room, your plants will only be able to photosynthesise a certain amount of light before needing a Co2 boost to benefit. Co2 is just not practical for your use.
Most magnetic ballasts can flip between MH/HPS these days. If you are willing to do some DIY, you can grab the bulb, ballast, ignitor and capacitor for around R600`. For a timer it is another R300 +- and a budget reflector from a grow shop is around R400.
Total for the whole system around R1300 +-