I think HIDs are legal as long as they are installed correctly and they don't blind oncomming traffic, you can get HID kits with a dual bulb so that on dipped beam they are like regular headlights and on high beam the HID part of it turns on so it dosen't matter if it blinds oncomming traffic (on high beam).

If you don't want to go the HID route the only options are to either replace your headlight with better quality ones that are rated for use with high wattage bulbs (i.e. 55w and up) or add extra lights. It isn't a good idea to up the wattage on your current headlight as I have found that cheap Chinese reflectors tend to melt if you use a bulb that runs as a higher wattage than what the reflector was intended for.

Since your bike dosen't have much room for mounting extra lights some mini LED lights like these should work pretty well.

http://www.ebay.co.uk/itm/1-Pair-4-C...item1e8079b2a2

If it was me I'd mount them on the front forks or under the front fairing.