I was looking for a pocket magnifier with a light a couple of years ago and I gave up because they all require expensive batteries. That would not be a problem if you only used it at shows or club meetings...but I was going to use it every day for at least an hour.
So then I started looking for a good lens and the prices scared me off. I wouldn't be so skittish about spending the money but I wasn't certain what I wanted exactly.
Anyway, one day I swiped my husband's microscope and bought him a better one for his birthday.
I don't like that the attached lights make taking photos just about impossible. But I haven't found on with a controllable light source.
If you find one with a controllable light source, that, I believe would be the best way to go.
Good luck shopping.