Another local source of fuel stabiliser may be anywhere people keep leasure boats, marinas, chandelrys etc , or garden machinery suppliers. Just make sure you get one specifically for ethanol blended fuels. Some of the older fuel stabilisers already have ethanol in and can make corrosion problems worse.
Stabil is another brand to look out for and seems popular with the boaty types.
http://www.goldeagle.com/product/marine-sta-bil-ethanol-fuel-treatment-stabilizer.
Most of the better brands come from the US because they have had to put up with ethanol in thier fuel longer than we have here.
Dave