I have long, narrow feet also.
Many of the more expensive brand names carry a "Narrow" or will
order it for you.
Naturalizer, SAS, I can't think of anymore off the top of my head
Go to a high-end shoe store. They have some great sales and will
measure you so you get just the right fit.
Another thing: when you put on your running shoes:
Before you tie the laces, put your heel down on the ground with
the toe facing upward to "seat" your heel in the shoe properly.
Then tie it.
This works for me before I take off and gives me a tighter fit so
i'm less likely to turn my ankle.