I did quite a bit of research but I'm no expert. Your inner geek might want to look here...Thanks for the replies everyone, will continue reading up in the next few days.
I've a very specific use, it's to inspect aircraft. Range needs to be around 30 meters at most, but I need to see with quite a level of clarity, hence my requirement for brightness. Also in a geek and cannot have just a "normal" flashlight, it needs to be brighter than the sun . Head lamp would be no use as it's got to point into lots of areas rather than just where I'm looking.
I need to look into these 14500 and 18650 cells. Where's a good place to buy them? I'm reluctant to buy non-branded cheapy lithium cells, having worked with traditional flat cells I like to know I'm buying good quality given their explosive nature if you get a dud.
http://lygte-info.dk/review/batteries2012/Common18650comparator.php
I ended up getting Sanyo cells and so far they're working very well.
Do some more reading because for what you describe i think you might want more flood ( it helps put what youre looking at in context) and light colour/warmth might be a factor. Also if you go for something very bright get something with a few settings because a light can be TOO bright to use for some purposes, and can reduce clarity.
I still think the Jetbeam IIM I mentioned a few posts upthread might be an option for you to consider.