That light looks very weak, even to be seen.

For a more usable light, kick up to a proper mounted flashlight. The UltraFire WF501b has been good for me. You can use it to see if you kick it up to medium or high, and it's an incredibly useful flashlight too.

Here it is with two batteries and charger for $16 shipped:
http://www.ebay.com/itm/310535278517

Add this to mount it:
http://www.ebay.com/itm/360699279195

For a taillight, my experience is limited to $30+ taillights so I can't help much. If you can find a Planet Bike Superflash or clone for < $15 that's decent. I can't say I think much of the dinky things like your 2nd link.

All of this stuff would go on and off your bike in 10 seconds.