I have two 6p Surefire originals (all round). One I have carried daily in a Blade tech upright holster for maybe 10 years. The other I bought as a spare( guy needed drinking money?). I would like to LED the spare with either KL3 LED conversion head or a KL5 LED conversion head to use as a leave on a long time light such as in a room or tent.This would not be for tactical situations as the other on fills that job fine. Which head should i spring for and why??