Raddi has a tire catalog sitting on the desk (brown cover at the center of the counter). I recently ordered some tires for my CBR 1000RR from Raddi, brand Shinko. I have been using Shinko for quite some time and have been more than happy with them. It took about 4-5 days to arrive from Manila. I also use Shink0 tires on my BMW 650 motocross (Raddi also supplied the tubes and tires for that bike as well).
If they can get tires for a 1000cc super bike and a motocross bike with a very odd tire sizes they shouldn't have any issues getting them for a 150cc.