First you have to decide why you want to use 123 cells. There arent many lights that will last 3-5 hours like you want with this battery. More like 1-2 hours. Unless you are going to buy 1/2 dozen rechargables and carry them around it will be expensive to get 5 hours of light.
You may want to consider the following AA lights that will last around 5 hours.
Fenix L2P or L2T (2AA) about 45 lumens nice moderate center and corona $40.00 or SL PP 4AA LUxeon
If you go with the Streamlight Propolymer 4AA Luxeon about 45 lumens but get the 4AA Luxeon definataly in YELLOW!
But I may be predjudiced! I got 2!
Incredible throw for the size and money. and decent spill in my opinion.
I bought mine for $28.00 from David Swards at
http://www.dlsenterprises.citymax.com/page/page/1718926.htm
877 829 8022 (Toll Free)
and would highly recommend him because he is a small 1 owner business and will talk to you as long as you want personally about lights on the phone. Excellent service. His shipping is less expensive than Fox's so it turns out about the same. I will order again from him! I am sure you could get it by the 14th.
Rechargables work well in both.
I have both of the above.