I found this thread a couple of years ago when I was looking for a rear light and bought the Cateye Rapid 3 which quite a few recommended and for the money is brilliant but is no longer available in the UK.
It seems manufacturers would now prefer to sell you a USB rechargeable knowing it only last a year or so before you have to go and buy a complete new unit for $25 as opposed to being able to just buy a new AA eneloop for less than $4