I would agree pretty much with what has been said so far.
The Badger 100LG with a fine tip is equal to the Iwata HP-B but neither are really reliable for modeling paints with the fine tip.
I have the 100LG and it has a medium tip and needle as that is how it was sent to me at Badger's recommendation for modeling.
I am an online Badger rep of sorts so I have many of their airbrushes to work with for comparison purposes. The best airbrush that Badger makes for the finest lines would be the Sotar 2020, although I don't know if you would need one or not. Here again I would use the Sotar with the medium tip as the fine tip is too finicky with modeling paints and was designed for inks, etc.
Your Badger 150 with a fine needle/tip combo should spray about as fine of a line as you would need, but being that it is a siphon-feed model the air pressure needs to be higher than a gravity-feed which causes you to lose the ability to spray fine lines with less overspray and control.
In order from finest lines to less precise airbrushes I would go with the Sotar 2020 at the top followed by the Badger 100LG, then maybe the Omni 4000/5000.
I hope this helped somewhat.
Mike
“Wisdom is the right use of knowledge. To know is not
to be wise. Many men know a great deal, and are all the greater fools
for it. There is no fool so great a fool as a knowing fool. But to know
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