It does depend on the type of riding you do. Do you want to see or be seen? Just to be seen- The Cateye EL300 is a good lamp, although if it is in well lit areas- I would prefer a flashing mode as this attracts attention better such as the EL410. These lights are just about ok as Backup up lights for more serious riding to supplement a better light.
Within your price- you should look at the Halogen lamps. If you want to see with them- go for a power in excess of 10w though and preferably a twin lamp with spot and flood. Battery life is another consideration so look at your riding and don't get a 2 hour battery if you are out for 3 hours at a time.
On the helmet lamps=I got a good enough one from a walking/ outdoor shop. Lots of types about but take your helmet to see if it will fit. Attachment shows the helmet lamp I use and the twin halogen is one I used last year and a link is to that one. The halogen was just about good enough to use offroad.
http://www.sjscycles.co.uk/product-S...9.99)-1886.htm