I have listed a ITorch Video Pro 3 focusing light whcih has done a handful of dives on Ebay. Its an excellent alternative to a Sola600 and it uses AA batteries which you can chnage between dives and its switch is bullet proof.
Auction starts at $200
http://www.ebay.com.au/itm/290853723657?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1558.l2649
The resaon for selling is that I have just bought 2 of the ITorch video 4